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Introduction: Neuronal ceroid lipofuscinosis (NCLs) is an autosomal recessive neurodegenerative disorders group. We report the first case in Colombia involving a new genetically confirmed variant of a homozygous CLN6 mutation. Case report: 12-year-old male, history of blood parents and average growth until 5 years of age. At this age began focal crises, progressive regression of neurodevelopment, severe cognitive deficit, and swallowing disorder that led to gastrostomy. Clinical exome + CNVs + mitochondrial DNA genetic study identified variant NM_017882.3 (CLN6): c. 22C>T, p. (Gln8*) in homozygous, deleterious. Late-onset infantile neuronal ceroid lipofuscinosis was diagnosed. Discussion: Mutations in the CLN6 gene are associated with late-onset infantile lipofuscinosis of autosomal recessive inheritance. This variant has not been previously described in the medical literature nor is it listed in the population databases, which indicates that it is extremely rare. The treatment focuses on the control of seizures, sleep disturbances, extrapyramidal symptoms, behavioral disorders, anxiety, and psychosis. Conclusion: To date, this variant of the CLN6 gene has not been reported in the world. There are currently no etiological or disease-specific therapeutic approaches. The use of exome/whole genome sequencing can be very useful for etiological diagnosis and differential diagnosis. An early diagnosis opens the door to future care and treatment.

Neuronal ceroid lipofuscinoses (NCLs) are a heterogeneous group of neurodegenerative diseases, characterized by progressive cerebral atrophy due to lysosomal storage disorder. Common clinical features include epileptic seizures, progressive cognitive and motor decline, and visual failure, which occur over different time courses according to subtypes. During the latest years, many advances have been done in the field of targeted treatments, and in the next future, gene therapies and enzyme replacement treatments may be available for several NCL variants. Considering that there is rapid disease progression in NCLs, an early diagnosis is crucial, and neurophysiological features might have a key role for this purpose. Across the different subtypes of NCLs, electroencephalogram (EEG) is characterized by a progressive deterioration of cerebral activity with slowing of background activity and disappearance of spindles during sleep. Some types of heterogeneous abnormalities, diffuse or focal, prevalent over temporal and occipital regions, are described in many NCL variants. Photoparoxysmal response to low-frequency intermittent photic stimulation (IPS) is a typical EEG finding, mostly described in CLN2, CLN5, and CLN6 diseases. Visual evoked potentials (VEPs) allow to monitor the visual functions, and the lack of response at electroretinogram (ERG) reflects retinal neurodegeneration. Taken together, EEG, VEPs, and ERG may represent essential tools toward an early diagnosis of NCLs.

Background: The incidence of neurological disorders is increasing due to population growth and extended life expectancy. Despite advances in the understanding of these disorders, curative strategies for treatment have not yet eventuated. In part, this is due to the complexities of the disorders and a lack of identification of their specific underlying pathologies. Dictyostelium discoideum has provided a useful, simple model to aid in unraveling the complex pathological characteristics of neurological disorders including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, neuronal ceroid lipofuscinoses and lissencephaly. In addition, D. discoideum has proven to be an innovative model for pharmaceutical research in the neurological field. Scope of review: This review describes the contributions of D. discoideum in the field of neurological research. The continued exploration of proteins implicated in neurological disorders in D. discoideum may elucidate their pathological roles and fast-track curative therapeutics.

Trabajo fin de grado en Enfermería, Introducción: En el último siglo, las enfermedades raras han pasado de ser un tema desatendido y aislado a cobrar importancia e interés por la mayor parte de la Comunidad Europea. La lipofuscinosis neuronal ceroidea tipo 2 es una de estas enfermedades raras que afecta a la población pediátrica y que tiene gran repercusión social, familiar y económica. Es necesario profundizar en relación a las estrategias de tratamiento relativas a esta enfermedad y, en particular, en el rol que tienen que desempeñar los profesionales de enfermería dentro de un programa multidisciplinar. Objetivo: Conocer la literatura existente en relación a las estrategias de tratamiento de la Lipofuscinosis Neuronal Ceroidea tipo 2 y el papel de enfermería en el manejo de la enfermedad. Método: Revisión narrativa mediante la búsqueda bibliográfica en bases de datos de Ciencias de la Salud: PubMed, LILACS, CUIDEN, CINAHL y Biblioteca Cochrane, y en buscadores generales: ScieLo España y Dialnet Plus. Resultados: Se identificó un total de 293 artículos de los que fueron seleccionados 29 que cumplían los criterios de inclusión y exclusión. El análisis de la información generó dos categorías: cuidados desde un enfoque multidisciplinar para el paciente pediátrico con Lipofuscinosis Neuronal Ceroidea tipo 2 y buenas prácticas para el uso de dispositivos intracerebroventriculares y administración de cerliponasa alfa. Conclusiones: La evidencia científica de la Lipofuscinosis Neuronal Ceroidea es escasa y se precisa del desarrollo de un protocolo de actuación que englobe todos sus cuidados. Es importante incluir la figura enfermera gestora de casos en el cuidado multidisciplinar, así como profesionales sanitarios especializados en enfermedades neurodegenerativas pediátricas para que la calidad de vida de los niños y sus cuidadores sea cada vez mejor., Introduction: In the last century, rare diseases have gone from being a neglected and isolated issue to gaining importance and interest in most of the European Community. Neuronal Ceroid Lipofuscinoses type 2 is one of these rare diseases that affects the pediatric population and has great social, family and economic repercussions. It is necessary to deepen in relation to the treatment strategies related to this disease and, in particular, in the role that nursing professionals have to play within a multidisciplinary program. Objective: To know the existing literature in relation to the treatment strategies of Neuronal Ceroid Lipofuscinoses type 2 and the role of nursing in the management of the disease. Methodology: Narrative review through bibliographic search in Health Sciences databases: PubMed, LILACS, CUIDEN, CINAHL and Cochrane Library, and in general search engines: ScieLo Spain and Dialnet Plus. Results: A total of 293 articles was identified. Finally, 29 that met the inclusion and exclusion criteria, were selected. The analysis of the information generated two categories: care from a multidisciplinary approach for the pediatric patient with Neuronal Ceroid Lipofuscinoses type 2 and good practices for the use of intracerebroventricular devices and administration of cerliponase alfa. Conclusions: The scientific evidence of Neuronal Ceroid Lipofuscinosis is scarce and the development of an action protocol that encompasses all its care is required. It is important to include the case manager nurse figure in multidisciplinary care, as well as health professionals specialized in pediatric neurodegenerative diseases so that the quality of life of children and their caregivers is increasingly better.

Neuronal ceroid lipofuscinoses (NCLs) are among the most common progressive encephalopathies of childhood. Neuronal ceroid lipofuscinosis 7 (CLN7), one of the late infantile-onset NCLs, is an autosomal recessive disorder caused by mutations in the MFSD8 gene on chromosome 4q28. Almost all reported mutations of MFSD8 in CLN7 patients were SNVs. However, we report a 4-year-old boy with CLN7 harboring compound heterozygous mutations in the MFSD8 gene, including one novel two-nucleotide deletion c.136_137delAT (p. M46Vfs*22) and one whole gene deletion of MFSD8 confirmed by Sanger sequencing, genomic quantitative PCR and CNV-seq. Therefore, for nonconsanguineous CLN7 patients with homozygous mutations in the MFSD8 gene, genetic counseling staff should focus on the possibility of whole gene deletion. This is one case report describing a whole gene deletion in a Chinese patient with CLN7, suggesting the diagnosis of CLN7 should be based on clinical suspicion and genetic testing.

Background: Ceroid lipofuscinoses neuronal 6 (CLN6) disease belongs to the neuronal ceroid lipofuscinoses (NCLs), complex and genetically heterogeneous disorders with wide geographical and phenotypic variation. The first clinical signs usually appear between 18months and 8 years, but examples of later-onset have also been reported. Common manifestations include ataxia, seizures, vision impairment, and developmental regression. Because these are shared by other neurological diseases, identification of CLN6 genetic variants is imperative for early diagnosis. Results: We present one of the largest cohorts to date of genetically diagnosed CLN6 patients screened at a single center. In total 97 subjects, originating from 20 countries were screened between 2010 and 2020. They comprised 86 late-infantile, eight juvenile, and three adult-onset cases (two patients with Kufs disease type A, and one with teenage progressive myoclonic epilepsy). The male to female ratio was 1.06: 1.00. The age at referral was between six months and 33years. The time from disease onset to referral ranged from less than 1 month to 8.3years. The clinical phenotype consisted of a combination of symptoms, as reported before.We characterized a total of 45 distinct variants defining 45 distinct genotypes. Twenty-four were novel variants, some with distinct geographic associations. Remarkably, c.257A > G (p.H86R) was present in five out of 23 unrelated Egyptian individuals but in no patients from other countries. The most common genotype was homozygosity for the c.794_796del in-frame deletion. It was present in about one-third of CLN6 patients (28 unrelated cases, and 2 familial cases), all with late-infantile onset. Variants with a high likelihood of causing loss of CLN6 function were found in 21% of cases and made up 33% of all distinct variants. Forty-four percent of variants were classified as pathogenic or likely pathogenic. Conclusions: Our study significantly expands the number of published clinical cases and the mutational spectrum of disease-associated CLN6 variants, especially for the Middle Eastern and North African regions. We confirm previous observations regarding the most prevalent symptoms and recommend including CLN6 in the genetic diagnosis of patients presenting with early-onset abnormalities of the nervous system, musculoskeletal system, and eye.

RESUMEN INTRODUCCIÓN: Las lipofuscinosis ceroideas neuronales (CLN) son un grupo de enfermedades neurodegenerativas de inicio generalmente en la infancia, caracterizadas por acumulación intracelular de material de almacenamiento autofluorescente. En la última década se han identificado 14 formas de CLN con mutaciones en 13 genes (CLN1-CLN14), en la CLN9 no se ha identificado aún el gen. Los pacientes con mutaciones en el gen CLN6 localizado en el cromosoma 15q21-23 presentan tres tipos de variantes clínicas: CLN6 infantil tardía, con presentación entre 18 meses a 8 años, las variantes Kufs tipo A y Kufs tipo B de inicio en adolescentes y adultos. REPORTE DE CASO: Se presenta el caso de un paciente con epilepsia generalizada de inicio en la edad adulta, que ingresa a valoración en primera ocasión, con resonancia magnética cerebral con atrofia cortical leve; la enfermedad se inició a los 14 años con déficit cognitivo lentamente progresivo, sin compromiso visual; con posterior identificación genética de una variante patogénica en el gen CLN6, con un conjunto de la variante clínica Kufs tipo A de lipofuscinosis ceroidea neuronal 6 (CLN6). DISCUSIÓN: Este es el primer reporte de CLN6 con variante clínica Kufs tipo A en Colombia. Con el advenimiento de técnicas genéticas se pueden hacer diagnósticos específicos de CLN6, a partir de la clínica y sospecha diagnóstica; utilizando métodos no invasivos. ABSTRACT INTRODUCTION: Neuronal ceroid lipofuscinosis (CLN) is a group of neurodegenerative diseases generally with onset in childhood, characterized by intracellular accumulation of autofluorescent storage material. In the last decade, 14 forms of CLN have been identified with mutations in 13 genes (CLN1-CLN14), in CLN9 the gene has not yet been identified. Patients with mutations in the CLN6 gene located on chromosome 15q21-23 present three types of clinical variants: late childhood CLN6, presenting between 18 months to 8 years, the Kufs type A and Kufs type B variants of onset in adolescents and adults. CASE REPORT: We present the case of a male patient with generalized epilepsy of onset in adulthood, who was admitted for evaluation the first time, with brain magnetic resonance imaging with mild cortical atrophy; he started at age 14 with slowly progressive cognitive deficit, without visual compromise; with subsequent genetic identification of a pathogenic variant in the CLN6 gene, jointly presenting the clinical variant Kufs type A of neuronal ceroid lipofuscinosis 6 (CLN6). DISCUSSION: This is the first report of CLN6 with Kufs type A clinical variant in Colombia. With the advent of genetic techniques, specific diagnoses of CLN6 can be made, based on the clinical and suspected diagnoses; using non-invasive methods.

Background Cathepsin D is a lysosomal aspartic protease encoded by the CTSD gene. It plays important roles in many biological processes. Biallelic loss‐of‐function mutation of CTSD is considered a cause of CLN10 disease. CLN10 is a rare autosomal recessive disorder that is one of 14 types of neuronal ceroid lipofuscinoses (NCLs). To date, only a few cases of CLN10 and 12 disease‐causing mutations have been reported worldwide. Methods Exome sequencing was performed on a 15‐year‐old girl with pervasive brain developmental disorder. The effects of the identified variants were investigated through multiple functional experiments. Results There were no differences in mRNA and protein expression, intracellular localization, maturation, and proteolytic activity between the cells with the mutant CTSD gene and those with the wild‐type CTSD gene. Conclusion These results suggest that the c.863A>G (p.Glu288Gly) homozygous variant is not a pathogenic variation, but a benign variant., Here, we report the novel variant c.863 A>G (p.Glu288Gly) of the CTSD gene in homozygous form, identified in a patient with an NCL‐like disorder. The effects of the variant on CatD expression, maturation, cellular localization, and enzymatic activity were studied. These results suggest that the c.863A>G (p.Glu288Gly) homozygous variant is not a pathogenic variation, but a benign variant.

This article presents datasets associated with the research article entitled “Intravitreal gene therapy protects against retinal dysfunction and degeneration in sheep with CLN5 Batten disease” (Murray et al., [1] ). The neuronal ceroid lipofuscinoses (NCL; Batten disease) are a group of fatal inherited diseases caused by mutations in a number of CLN genes that lead to degenerative and fatal encephalopathies in children. Naturally-occuring sheep models of NCL exist. Affected sheep share the clinical and pathological features of the human disease, including retinal degeneration. Electroretinography (ERG) was employed to characterise the physiological changes in the degenerating retina of CLN5 and CLN6 forms of ovine NCL. ERGs were performed every two months from 3 to 17 months of age in 11 NCL affected (6 CLN5−/− and 5 CLN6−/−) sheep and 12 clinically normal heterozygous controls (6 CLN5+/− and 6 CLN6+/−) under three different adaptation conditions. A-wave and b-wave amplitudes were collected from each eye using the Eickemeyer Veterinary ERG system. These are the first longitudinal datasets assessing the progression of retinal degeneration in ovine NCL, aiding in characterisation of the disease process and providing insight into optimal therapeutic windows for subsequent studies.

Neuronal ceroid lipofuscinoses (NCL, Batten disease) are a group of inherited neurodegenerative diseases characterized by age-related onset, progressive myoclonus epilepsy, visual impairment and progressive intellectual and motor disorders. In all forms of NCL, the pathological autofluorescent lipopigment accumulates in the brain and other tissues. The diagnosis is made following determination of the activity of specific enzymes in blood leukocytes or cell culture of skin fibroblasts and investigation of biopsy specimens with electron microscopy as well as molecular genetic research. The article presents a patient with the onset of the disease at the age of 3 with epileptic tonic-clonic seizures, with further progression of the disease in the form of myoclonic seizures, motor pyramidal and cerebellar disorders, as well as intellectual, mnestic and speech disturbances. The presented clinical case demonstrates difficulties in the diagnosis of neurodegenerative diseases at onset, as well as the absence of pathognomonic signs of the disease during neurophysiological and neuroimaging examinations, which makes it necessary to conduct additional molecular and genetic research

Neuronal ceroid lipofuscinoses (NCLs) are a group of rare neurodegenerative storage disorders associated with devastating visual prognosis, with an incidence of 1/1,000,000 in the United States and comparatively higher incidence in European countries. The pathophysiological mechanisms causing NCLs occur due to enzymatic or transmembrane defects in various sub-cellular organelles including lysosomes, endoplasmic reticulum, and cytoplasmic vesicles. NCLs are categorized into different types depending upon the underlying cause i.e., soluble lysosomal enzyme deficiencies or non-enzymatic deficiencies (functions of identified proteins), which are sub-divided based on an axial classification system. In this review, we have evaluated the current evidence in the literature and reported the incidence rates, underlying mechanisms and currently available management protocols for these rare set of neuroophthalmological disorders. Additionally, we also highlighted the potential therapies under development that can expand the treatment of these rare disorders beyond symptomatic relief.

Cathepsin D (CTSD) is a lysosomal protease important for the degradation of various substrates, including disease-associated proteins like α-synuclein (a-syn), amyloid precursor protein (APP) and tau, all of which tend to aggregate if not efficiently degraded. Hence, it is not surprising that genetic variants within the CTSD gene have been linked to neurodegenerative diseases, like Parkinson’s and Alzheimer’s disease (PD, AD), as well as the lysosomal storage disorder neuronal ceroid lipofuscinosis type-10 (NCL10). Although recent studies have shown the molecular dependence of substrate degradation via CTSD within autophagic pathways, only little is known about the precise role of lysosomal CTSD function in disease development. We here performed biochemical, cellular and structural analyses of eleven disease-causing CTSD point mutations found in genomic sequencing data of patients to understand their role in neurodegeneration. These CTSD variants were analyzed for cellular localization, maturation and enzymatic activity in overexpression analyses. Moreover, for PD-associated mutants, intracellular degradation of a-syn was monitored. In summary, our results suggest that NCL10-associated CTSD variants are significantly impaired in lysosomal maturation and enzymatic activity, whereas the AD- and PD-associated variants seemed rather unaffected, indicating normal maturation, and lysosomal presence. Interestingly, a PD-associated CTSD variant (A239V) exhibited increased enzymatic activity accompanied by enhanced a-syn degradation. By structural analyses of this mutant utilizing molecular dynamics simulation (MDS), we identified a structural change within a loop adjacent to the catalytic center leading to a higher flexibility and potentially accelerated substrate exchange rates. Our data sheds light onto the role of CTSD in disease development and helps to understand the structural regulation of enzymatic function, which could be utilized for targeted CTSD activation. Because of the degradative function of CTSD, this enzyme is especially interesting for therapeutic strategies tackling protein aggregates in neurodegenerative disorders.

Background Neuronal ceroid lipofuscinoses, (NCLs or Batten disease) are a group of inherited, early onset, fatal neurodegenerative diseases associated with mutations in 13 genes. All forms of the disease are characterized by lysosomal accumulation of fluorescent storage material, as well as profound neurodegeneration, but the relationship of the various genes’ function to a single biological process is not obvious. In this study, we used a well-characterized mouse model of classical late infantile NCL (cLINCL) in which the tripeptidyl peptidase 1 (Tpp1) gene is disrupted by gene targeting, resulting in loss of detectable TPP1 activity and leading to progressive neurological phenotypes including ataxia, increased motor deficiency, and early death. Methods In order to identify genes and pathways that may contribute to progression of the neurodegenerative process, we analyzed forebrain/midbrain and cerebellar transcriptional differences at 1, 2, 3 and 4 months of age in control and TPP1-deficient mice by global RNA-sequencing. Results Progressive neurodegenerative inflammatory responses involving microglia, astrocytes and endothelial cells were observed, accompanied by activation of leukocyte extravasation signals and upregulation of nitric oxide production and reactive oxygen species. Several astrocytic (i.e., Gfap, C4b, Osmr, Serpina3n) and microglial (i.e., Ctss, Itgb2, Itgax, Lyz2) genes were identified as strong markers for assessing disease progression as they showed increased levels of expression in vivo over time. Furthermore, transient increased expression of choroid plexus genes was observed at 2 months in the lateral and fourth ventricle, highlighting an early role for the choroid plexus and cerebrospinal fluid in the disease pathology. Based on these gene expression changes, we concluded that neuroinflammation starts, for the most part, after 2 months in the Tpp1−/− brain and that activation of microglia and astrocytes occur more rapidly in cerebellum than in the rest of the brain; confirming increased severity of inflammation in this region. Conclusions These findings have led to a better understanding of cLINCL pathological onset and progression, which may aid in development of future therapeutic treatments for this disease.

Background: The neuronal ceroid lipofuscinoses (NCL) constitute a group of gray matter neurodegenerative disorders characterized by the accumulation of ceroid lipopigment in lysosomes in neurons and other cell types. There are very few published studies on NCL from India, especially in children. Methods: A retrospective study of confirmed patients of NCL diagnosed over a period of 10 years from January 2019 to December 2019. Results: Fifty children had a definitive diagnosis of NCL based on enzymatic studies or genetic testing using next-generation sequencing. Around 15 children were diagnosed to have CLN-1 (ceroid lipofuscinoses, neuronal-1) based on palmitoyl protein thioesterase-1 deficiency; 24 children were diagnosed with CLN2 (ceroid lipofuscinoses, neuronal-2) based on deficient tripeptidyl-peptidase-1 activity; three patients were diagnosed as CLN6, five patients as CLN7, one case each of CLN8, CLN11, and CLN14 based on genetic testing. Clinical presentation was quite varied and included refractory seizures, developmental delay/regression, and abnormal movements. Visual failure was not common in the present case series. Neuroimaging patterns in different types of NCL were different. All children had a progressive downhill course resulting in death in many over a period of 5–10 years of disease onset. Conclusion: NCL is not uncommon and diagnosis can be suspected based on clinical investigations and neuroimaging findings. Diagnosis can be confirmed by enzymatic assays or genetic testing.

Introduction and purpose Neuronal ceroid lipofuscinoses (NCLs) is a group of congenital metabolic diseases where the neurodegenerative process with the accumulation of ceroid and lipofuscin autofluorescent storage materials is at the forefront. According to the age of presentation, NCLs are classified as congenital, infantile (INCL), late infantile (LINCL), juvenile (JNCL), and adult (ANCL) NCLs. In our study, it was aimed to discuss the clinical and molecular characteristics of our patients diagnosed with NCL. Material and method This is a descriptive cross-sectional study which was conducted in 14 patients from 10 unrelated families who were diagnosed with different types of NCL based on clinical presentation, neuroimaging, biochemical measurements, and molecular analyses, at the department of pediatric metabolism between June 2015 and June 2020. Results A total of 14 patients were diagnosed with different types of NCL. Of those, 4 patients were diagnosed with NCL7 (4/14; 30%), 3/14 (23%) with NCL1, 3/14 (23%) with NCL2, 2/14 (14.2%) with NCL13, and 1/14 (7.1%) with NCL10. Eleven pathogenic variants were detected, 5 of which are novel (c.721G>T [p.Gly241Ter] and c.301G>C [p.Ala146Pro] in MFDS8 gene; c.316C>T [p.Gln106Ter] in PPT1 gene; c.341C>T [p.Ala114Val] in TPP1 gene; c.686A>T [p.Glu229Val] in CTSD gene) Conclusion This study is one of the pioneer comprehensive researches from Turkey that provides information about disease-causing variants and clinical presentation of different and rare types of NCLs. The identification of novel variants and phenotypic expansion is important for genetic counselling in Turkey and expected to improve understanding of NCLs.

Neuronal ceroid lipofuscinoses (NCLs), also referred as “Batten disease”, are a group of thirteen rare genetic conditions, which are part of the lysosomal storage disorders. CLN type 2 (CLN2) is caused by the deficient activity of the tripeptidyl peptidase I (TPP1) enzyme, encoded by the TPP1 gene, most frequently leading to the classic late infantile phenotype. Nearly 140 CLN2-causing mutations have been described. In this case report, we describe the identification of a new disease-causing mutation and highlight the importance of appropriate laboratory investigation based on clinical suspicion. The collection of dried blood spots (DBS) on filter paper, which is a convenient sample, can be used to measure the TPP1 enzyme activity and detect CLN2-related mutations. Since the biochemical and genetic diagnoses are possible and as the disease progression is fast and the therapeutic window is short, the investigation of CLN2 should be always considered when this diagnostic hypothesis is raised in order to enable the patients to benefit from the specific pharmacological treatment.

The neuronal ceroid lipofuscinoses (NCLs) collectively constitute one of the most common forms of inherited childhood-onset neurodegenerative disorders. They form a heterogeneous group of incurable lysosomal storage diseases that lead to blindness, motor deterioration, epilepsy, and dementia. Traditionally the NCL diseases were classified according to the age of disease onset (infantile, late-infantile, juvenile, and adult forms), with at least 13 different NCL varieties having been described at present. The current review focuses on classic juvenile NCL (JNCL) or the so-called Batten (Batten-Spielmeyer-Vogt; Spielmeyer-Sjogren) disease, which represents the most common and the most studied form of NCL, and is caused by mutations in the CLN3 gene located on human chromosome 16. Most JNCL patients carry the same 1.02-kb deletion in this gene, encoding an unusual transmembrane protein, CLN3, or battenin. Accordingly, the names CLN3-related neuronal ceroid lipofuscinosis or CLN3-disease sometimes have been used for this malady. Despite excessive in vitro and in vivo studies, the precise functions of the CLN3 protein and the JNCL disease mechanisms remain elusive and are the main subject of this review. Although the CLN3 gene is highly conserved in evolution of all mammalian species, detailed analysis of recent genomic and transcriptomic data indicates the presence of human-specific features of its expression, which are also under discussion. The main recorded to date changes in cell metabolism, to some extent contributing to the emergence and progression of JNCL disease, and human-specific molecular features of CLN3 gene expression are summarized and critically discussed with an emphasis on the possible molecular mechanisms of the malady appearance and progression.

Background Neuronal ceroid lipofuscinosis type 5 (CLN5) is a rare form of neuronal ceroid lipofuscinoses (NCLs) which are a group of inherited neurodegenerative diseases characterized by progressive intellectual and motor deterioration, visual failure, seizures, behavioral changes and premature death. CLN5 was initially named Finnish variant late infantile NCL, it is now known to be present in other ethnic populations and with variable age of onset. Few CLN5 patients had been reported in Chinese population. Case presentation In this paper, we report the symptoms of a Chinese patient who suffer from developmental regression and grand mal epilepsy for several years. The DNA was extracted from peripheral blood of proband and both parents, and then whole exome sequencing was performed using genomic DNA. Both sequence variants and copy number variants (CNVs) were analyzed and classified according to guidelines. As the result, a novel frameshift mutation c.718_719delAT/p.Met240fs in CLN5 and a de novo large deletion at 13q21.33-q31.1 which unmasked the frameshift mutation were identified in the proband. Despite the large de novo deletion, which can be classified as a pathogenic copy number variant (CNV), the patient’s clinical presentation is mostly consistent with that of CLN5, except for early developmental delay which is believed due to the large deletion. Both variants were detected simultaneously by exome sequencing. Conclusions This is the first report of whole gene deletion in combination with a novel pathogenic sequence variant in a CLN5 patient. The two mutations detected with whole exome sequencing simultaneously proved the advantage of the sequencing technology for genetic diagnostics.

Neuronal ceroid lipofuscinoses (NCLs) are a group of autosomal recessive inherited neurodegenerative disorders mainly affecting children, and at least 13 causative genes (CLN1 to CLN8 and CLN10 to CLN14) have been identified. Here, we reported a novel homozygous missense mutation (c.434G > C, p.Arg145Pro) identified in CLN5 gene via whole exome sequencing in a 5-year-old girl. The patient first presented paroxysmal epilepsy associated with vomiting, followed by progressive regression in walking, vision, intelligence and speaking. Combining the molecular and clinical analysis, the diagnosis of NCL could be made, although the missense mutation (c.434G > C, p.Arg145Pro) in CLN5 was evaluated to be a variant of uncertain significance according to American College of Medical Genetics and Genomics (ACMG) standard. We further performed expression and localization studies and our results provide evidence of impaired cellular trafficking of CLN5 to lysosome, indicating that this mutation might be deleterious to the function of CLN5 for its mislocalization. Our study demonstrated the efficacy of next generation sequencing in molecular diagnosis, and a deleterious effect of the variant discovered in our patient on CLN5, triggering the NCL disease.

The neuronal ceroid lipofuscinoses are a class of inherited neurodegenerative diseases characterized by the accumulation of autofluorescent storage material. The most common neuronal ceroid lipofuscinosis has juvenile onset with rapid onset blindness and progressive degeneration of cognitive processes. The juvenile form is caused by mutations in the CLN3 gene, which encodes the protein CLN3. While mouse models of Cln3 deficiency show mild disease phenotypes, it is apparent from patient tissue- and cell-based studies that its loss impacts many cellular processes. Using Cln3 deficient mice, we previously described defects in mouse brain endothelial cells and blood-brain barrier (BBB) permeability. Here we expand on this to other components of the BBB and show that Cln3 deficient mice have increased astrocyte endfeet area. Interestingly, this phenotype is corrected by treatment with a commonly used GAP junction inhibitor, carbenoxolone (CBX). In addition to its action on GAP junctions, CBX has also been proposed to alter lipid microdomains. In this work, we show that CBX modifies lipid microdomains and corrects membrane fluidity alterations in Cln3 deficient endothelial cells, which in turn improves defects in endocytosis, caveolin-1 distribution at the plasma membrane, and Cdc42 activity. In further work using the NIH Library of Integrated Network-based Cellular Signatures (LINCS), we discovered other small molecules whose impact was similar to CBX in that they improved Cln3-deficient cell phenotypes. Moreover, Cln3 deficient mice treated orally with CBX exhibited recovery of impaired BBB responses and reduced auto-fluorescence. CBX and the compounds identified by LINCS, many of which have been used in humans or approved for other indications, may find therapeutic benefit in children suffering from CLN3 deficiency through mechanisms independent of their original intended use.

Neural stem/progenitor cells (NPCs) generate new neurons in the brain throughout an individual's lifetime in an intricate process called neurogenesis. Neurogenic alterations are a common feature of several adult-onset neurodegenerative diseases. The neuronal ceroid lipofuscinoses (NCLs) are the most common group of inherited neurodegenerative diseases that mainly affect children. Pathological features of the NCLs include accumulation of lysosomal storage material, neuroinflammation and neuronal degeneration, yet the exact cause of this group of diseases remains poorly understood. The function of the CLN5 protein, causative of the CLN5 disease form of NCL, is unknown. In the present study, we sought to examine neurogenesis in the neurodegenerative disorder caused by loss of Cln5. Our findings demonstrate a newly identified crucial role for CLN5 in neurogenesis. We report for the first time that neurogenesis is increased in Cln5-deficient mice, which model the childhood neurodegenerative disorder caused by loss of Cln5. Our results demonstrate that, in Cln5 deficiency, proliferation of NPCs is increased, NPC migration is reduced and NPC differentiation towards the neuronal lineage is increased concomitantly with functional alterations in the NPCs. Moreover, the observed impairment in neurogenesis is correlated with increased expression of the pro-inflammatory cytokine IL-1β. A full understanding of the pathological mechanisms that lead to disease and the function of the NCL proteins are critical for designing effective therapeutic approaches for this devastating neurodegenerative disorder., Editors’ choice: This study demonstrates neurogenic alterations in the most common neurodegenerative disease of children and reports a novel function of the CLN5 protein.

Summary Defective lysosomal function defines many neurodegenerative diseases, such as neuronal ceroid lipofuscinoses (NCL) and Niemann-Pick type C (NPC), and is implicated in Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD-TDP) with progranulin (PGRN) deficiency. Here, we show that PGRN is involved in lysosomal homeostasis and lipid metabolism. PGRN deficiency alters lysosome abundance and morphology in mouse neurons. Using an unbiased lipidomic approach, we found that brain lipid composition in humans and mice with PGRN deficiency shows disease-specific differences that distinguish them from normal and other pathologic groups. PGRN loss leads to an accumulation of polyunsaturated triacylglycerides, as well as a reduction of diacylglycerides and phosphatidylserines in fibroblast and enriched lysosome lipidomes. Transcriptomic analysis of PGRN-deficient mouse brains revealed distinct expression patterns of lysosomal, immune-related, and lipid metabolic genes. These findings have implications for the pathogenesis of FTLD-TDP due to PGRN deficiency and suggest lysosomal dysfunction as an underlying mechanism., Graphical abstract

Background: Metaphors are often used within the context of ethics and healthcare but have hardly been explored in relation to moral reasoning. Objective: To describe a central set of metaphors in one case and to explore their contribution to moral reasoning. Method: Semi-structured interviews were conducted with 16 parents of a child suffering from the neurodegenerative disease CLN3. The interviews were recorded, transcribed, and metaphors were analyzed. The researchers wrote memos and discussed about their analyses until they reached consensus. Ethical considerations: Participants gave oral and written consent and their confidentiality and anonymity were respected. Findings: A central set of metaphors referred to the semantic field of the hands and arms and consisted of two central metaphors that existed in a dialectical relationship: grasping versus letting go. Participants used these metaphors to describe their child’s experiences, who had to “let go” of abilities, while “clinging” to structures and the relationship with their parent(s). They also used it to describe their own experiences: participants tried to “grab” the good moments with their child and had to “let go” of their child when (s)he approached death. Participants, in addition, “held” onto caring for their child while being confronted with the necessity to “let go” of this care, leaving it to professional caregivers. Discussion: The ethical analysis of the findings shows that thinking in terms of the dialectical relationship between “grasping” and “letting go” helps professional caregivers to critically think about images of good care for children with CLN3. It also helps them to bear witness to the vulnerable, dependent, and embodied nature of the moral self of children with CLN3 and their parents. Conclusion: Metaphorical reasoning may support the inclusion of marginalized perspectives in moral reasoning. Future studies should further explore the contribution of metaphorical reasoning to moral reasoning in other cases.

Background Neuronal ceroid lipofuscinoses are neurodegenerative disorders. To investigate the diagnostic yield of direct Sanger sequencing of the CLN genes, we reviewed Molecular Genetics Laboratory Database for molecular genetic test results of the CLN genes from a single clinical molecular diagnostic laboratory. Methods We reviewed electronic patient charts. We used consent forms and Research Electronic Data Capture questionnaires for the patients from outside of our Institution. We reclassified all variants in the CLN genes. Results Six hundred and ninety three individuals underwent the direct Sanger sequencing of the CLN genes for the diagnosis of neuronal ceroid lipofuscinoses. There were 343 symptomatic patients and 350 family members. Ninety‐one symptomatic patients had molecular genetic diagnosis of neuronal ceroid lipofuscinoses including CLN1 (PPT1) (n = 10), CLN2 (TPP1) (n = 33), CLN3 (n = 17), CLN5 (n = 7), CLN6 (n = 10), CLN7 (MFSD8) (n = 10), and CLN8 (n = 4) diseases. The diagnostic yield of direct Sanger sequencing of CLN genes was 27% in symptomatic patients. We report detailed clinical and investigation results of 33 NCL patients. Juvenile onset CLN1 (PPT1) and adult onset CLN6 diseases were nonclassical phenotypes. Conclusion In our study, the diagnostic yield of direct Sanger sequencing was close to diagnostic yield of whole exome sequencing. Developmental regression, cognitive decline, visual impairment and cerebral and/or cerebellar atrophy in brain MRI are significant clinical and neuroimaging denominators to include NCL in the differential diagnosis.

In humans, homozygous mutations in the TPP1 gene results in loss of tripeptidyl peptidase 1 (TPP1) enzymatic activity, leading to late infantile neuronal ceroid lipofuscinoses disease. Using a mouse model that targets the Tpp1 gene and recapitulates the pathology and clinical features of the human disease, we analyzed end-stage (4 months) transcriptional changes associated with lack of TPP1 activity. Using RNA sequencing technology, Tpp1 expression changes in the forebrain/midbrain and cerebellum of 4-month-old homozygotes were compared with strain-related controls. Transcriptional changes were found in 510 and 1,550 gene transcripts in forebrain/midbrain and cerebellum, respectively, from Tpp1-deficient brain tissues when compared with age-matched controls. Analysis of the differentially expressed genes using the Ingenuity™ pathway software, revealed increased neuroinflammation activity in microglia and astrocytes that could lead to neuronal dysfunction, particularly in the cerebellum. We also observed upregulation in the production of nitric oxide and reactive oxygen species; activation of leukocyte extravasation signals and complement pathways; and downregulation of major transcription factors involved in control of circadian rhythm. Several of these expression changes were confirmed by independent quantitative polymerase chain reaction and histological analysis by mRNA in situ hybridization, which allowed for an in-depth anatomical analysis of the pathology and provided independent confirmation of at least two of the major networks affected in this model. The identification of differentially expressed genes has revealed new lines of investigation for this complex disorder that may lead to novel therapeutic targets.

The article contains raw and analyzed data related to the research article “Neuronal ceroid lipofuscinosis genes, CLN2, CLN3, CLN5 are spatially and temporally co-expressed in a developing mouse brain” (Fabritius et al., 2014) [1]. The processed data gives an understanding of the development of the cell types that are mostly affected by defective function of CLN proteins, timing of expression of CLN1, CLN2, CLN3 and CLN5 genes in a murine model. The data shows relationship between the expression pattern of these genes during neural development. Immunohistochemistry was used to identify known interneuronal markers for neurotransmission and cell proliferation: parvalbumin, somatostatin subpopulations of interneurons. Non-radioactive in-situ hybridization detected CLN5 mRNA in the hippocampus. Throughout the development strong expression of CLN genes were identified in the germinal epithelium and in ventricle regions, cortex, hippocampus, and cerebellum. This provides supportive evidence that CLN1, CLN2, CLN3 and CLN5 genes may be involved in synaptic pruning. Keywords: Neurogenetics, CLN genes, CLN1/CLN2/CLN3/CLN5, Embryonic neurogenesis, Neurotransmission, molecular genetics, Neuronal ceroid lipofuscinoses, Neuronal differentiation, neuroplasticity, and synaptic pruning

The neuronal ceroid lipofuscinoses are a group of severe and progressive neurodegenerative disorders, which generally present during childhood. With new treatments emerging on the horizon, there is a growing need to understand the specific disease mechanisms as well as identify prospective biomarkers for use to stratify patients and monitor treatment. The use of Omics technologies to NCLs have the potential to address this need. We discuss the recent use and outcomes of Omics to various forms of NCL including identification of interactomes, affected biological pathways and potential biomarker candidates. We also identify commonpathways affected in NCL across the reviewed studies.

The neuronal ceroid lipofuscinoses (NCLs) are autosomal recessive diseases with progressive dementia, motor disturbance, epilepsy, visual loss and early death, affecting mainly children but also adults. Mutations in 13 distinct genes cause NCLs with marked phenotypic heterogeneity and undefined pathomechanism. CLN8 gene shows wide complexity with 31 different mutations leading to late-infantile NCL variants (vLINCL) and progressive epilepsy with mental retardation (EPMR) (www.ucl.ac.uk/ncl/mutation.shtml). CLN8 encodes an ER-resident transmembrane protein with an ER-ERGIC retrieval signal, a TLC domain normally related to lipid sensing/trafficking, and possible multiple roles (1, 2). We proposed to study the functional meaning of CLN8-VAPA interaction previously characterized (Passantino et al., 2013), being VAPA an ER-docking-site for cytosolic lipid-binding-proteins responsible of ceramide transport, sphingolipid (SL), phospholipid and cholesterol synthesis/trafficking. We expect to define CLN8 implication in SL, and pinpoint the molecular bases of the phenotypic heterogeneity. In the frame of the current project, using recombinant proteins and mammalian expression vectors (mono/bicistronic) encoding flCLN8, its subregions and flVAPA, and in vitro and in vivo assays, we identified a putative CLN8 region interacting with VAPA, that is highly conserved in vertebrates and bears some vLINCL mutations. In vitro SphingoStrips and TLC overlay assay revealed no direct binding of flCLN8 and subregions to ceramides;whereas, metabolic labeling studies showed kinetic changes in the ceramide pathway of HeLa cells overexpressing CLN8 and VAPA. Interestingly, CLN8 (presumably the N-terminus) was able to bind sulfatide, which regulates myelination; considering the myelin defects in NCLs (3), further studies are ongoing. Throughout site-directed-mutagenesis, we created a model of EPMR-type mutation. In cells expressing both EPMR and VAPA, we found a strong EPMR-VAPA interaction and higher sphingomyelin and cholesterol levels. We also generated CRISPR/Cas9 CLN8 KO clones that show to maintain survival and migration capacities similar to native HeLa cell line but grow as autophagy predisposed cells. In CLN8-KO clones, even though the high VAPA levels, the only difference observed in sphingolipid was a marked change in the ganglioside patterns, with a shift toward more complex species. The overall results indicate a multifaceted and at least in part novel role of CLN8 alone and with VAPA toward SL trafficking, also supported by the finding that flCLN8 and subregions were able to bind different phosphoinositides in vitro. We are underway using the newly created CRISPR-CERT KO clones to analyze this ceramide transporter as part of CLN8-VAPA complex and possible target of CLN8 dysfunction. Fibroblast cells of patients with CLN8-vLINCL and EPMR are being used to correlate phenotype/genotype divergences to the CLN8-VAPA complex.

Background CLN6-Batten disease is a rare neurodevelopmental disorder characterized pathologically by the accumulation of lysosomal storage material, glial activation and neurodegeneration, and phenotypically by loss of vision, motor coordination, and cognitive ability, with premature death occurring in the second decade of life. In this study, we investigate whether sex differences in a mouse model of CLN6-Batten disease impact disease onset and progression. Results A number of noteworthy differences were observed including elevated accumulation of mitochondrial ATP synthase subunit C in the thalamus and cortex of female Cln6 mutant mice at 2 months of age. Moreover, female mutant mice showed more severe behavioral deficits. Beginning at 9 months of age, female mice demonstrated learning and memory deficits and suffered a more severe decline in motor coordination. Further, compared to their male counterparts, female animals succumbed to the disease at a slightly younger age, indicating an accelerated disease progression. Conversely, males showed a marked increase in microglial activation at 6 months of age in the cortex relative to females. Conclusions Thus, as female Cln6 mutant mice exhibit cellular and behavioral deficits that precede similar pathologies in male mutant mice, our findings suggest the need for consideration of sex-based differences in CLN6 disease progression during development of preclinical and clinical studies. Electronic supplementary material The online version of this article (10.1186/s13023-019-0994-8) contains supplementary material, which is available to authorized users.

Background Neuronal ceroid lipofuscinoses (NCLs) are one of the most frequent childhood-onset neurodegenerative pathologies characterized by seizures, progressive cognitive decline, motor impairment and loss of vision. For the past two decades, more than 430 variants in 13 candidate genes have been identified in the affected patients. Most of the variants were almost exclusively reported in Western patients, and very little clinical and genetic information was available for Chinese patients. Case presentation We report a Chinese boy whose clinical phenotypes were suspected to be NCL, including intractable epilepsy, cognitive and motor decline and progressive vision loss. Using targeted next-generation sequencing, two novel null variants in CLN8 (c.298C > T, p.Gln100Ter; c.551G > A, p.Trp184Ter) were detected in this patient in trans model. These two variants were interpreted as pathogenic according to the variant guidelines of the American College of Medical Genetics and Genomics. Conclusions This is the first case report of NCL due to CLN8 variants in China. Our findings expand the variant diversity of CLN8 and demonstrate the tremendous diagnosis value of targeted next-generation sequencing for pediatric NCLs. Electronic supplementary material The online version of this article (10.1186/s12881-018-0535-7) contains supplementary material, which is available to authorized users.

Studies on naturally occurring New Zealand and Australian ovine models of the neuronal ceroid-lipofuscinoses (Batten disease, NCLs) have greatly aided our understanding of these diseases. Close collaborations between the New Zealand groups at Lincoln University and the University of Otago, Dunedin, and a group at the University of Sydney, Australia, led to the formation of BARN, the Batten Animal Research Network. This review focusses on presentations at the 14th International Conference on Neuronal Ceroid Lipofuscinoses (Batten Disease), recent relevant background work, and previews of work in preparation for publication. Themes include CLN5 and CLN6 neuronal cell culture studies, studies on tissues from affected and control animals and whole animal in vivo studies. Topics include the effect of a CLN6 mutation on endoplasmic reticulum proteins, lysosomal function and the interactions of CLN6 with other lysosomal activities and trafficking, scoping gene-based therapies, a molecular dissection of neuroinflammation, identification of differentially expressed genes in brain tissue, an attempted therapy with an anti-inflammatory drug in vivo and work towards gene therapy in ovine models of the NCLs. This article is part of a Special Issue entitled: "Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)".

The fatal, primarily childhood neurodegenerative disorders, neuronal ceroid lipofuscinoses (NCLs), are currently associated with mutations in 13 genes. The protein products of these genes (CLN1 to CLN14) differ in their function and their intracellular localization. NCL-associated proteins have been localized mostly in lysosomes (CLN1, CLN2, CLN3, CLN5, CLN7, CLN10, CLN12 and CLN13) but also in the Endoplasmic Reticulum (CLN6 and CLN8), or in the cytosol associated to vesicular membranes (CLN4 and CLN14). Some of them such as CLN1 (palmitoyl protein thioesterase 1), CLN2 (tripeptidyl-peptidase 1), CLN5, CLN10 (cathepsin D), and CLN13 (cathepsin F), are lysosomal soluble proteins; others like CLN3, CLN7, and CLN12, have been proposed to be lysosomal transmembrane proteins. In this review, we give our views and attempt to summarize the proposed and confirmed functions of each NCL protein and describe and discuss research results published since the last review on NCL proteins. This article is part of a Special Issue entitled: "Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”.

This article addresses the educational issues associated with rare diseases (RD) and in particular the Neuronal Ceroid Lipofuscinoses (NCLs, or CLN diseases) in the curricula of Health Sciences and Professional's Training Programs. Our aim is to develop guidelines for improving scientific knowledge and practice in higher education and continuous learning programs.Rare diseases (RD) are collectively common in the general population with 1 in 17 people affected by a RD in their lifetime. Inherited defects in genes involved in metabolism are the commonest group of RD with over 8000 known inborn errors of metabolism. The majority of these diseases are neurodegenerative including the NCLs. Any professional training program on NCL must take into account the medical, social and economic burdens related to RDs. To address these challenges and find solutions to them it is necessary that individuals in the government and administrative authorities, academia, teaching hospitals and medical schools, the pharmaceutical industry, investment community and patient advocacy groups all work together to achieve these goals.The logistical issues of including RD lectures in university curricula and in continuing medical education should reflect its complex nature. To evaluate the state of education in the RD field, a summary should be periodically up dated in order to assess the progress achieved in each country that signed up to the international conventions addressing RD issues in society. It is anticipated that auditing current practice will lead to higher standards and provide a framework for those educators involved in establishing RD teaching programs world-wide. Fil: Cismondi, Inés Adriana. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina Fil: Kohan, Romina. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina Fil: Adams, Heather. University Of Rochester School Of Medicine And Dentistry; Estados Unidos Fil: Bond, Mike. Colegio Universitario de Londres; Reino Unido Fil: Brown, Rachel. Colegio Universitario de Londres; Reino Unido Fil: Cooper, Jonathan D.. King's College London; Reino Unido Fil: de Hidalgo, Perla K.. Universidad Nacional de Córdoba; Argentina Fil: Holthaus, Sophia Martha Kleine. Ucl Institute Of Ophthalmology; Reino Unido. Colegio Universitario de Londres; Reino Unido Fil: Mole, Sara E.. Colegio Universitario de Londres; Reino Unido Fil: Mugnaini, Julia. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Oller de Ramirez, Ana María. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina Fil: Pesaola, Favio Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina Fil: Rautenberg, Gisela Evelín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina Fil: Platt, Frances M.. University of Oxford; Reino Unido Fil: Noher, Rita Ines. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina

The neuronal ceroid lipofuscinoses (NCL) currently encompass fourteen genetically different forms, CLN1 to CLN14, but are all morphologically marked by loss of nerve cells, particularly in the cerebral and cerebellar cortices, and the cerebral and extracerebral formation of lipopigments. These lipopigments show distinct ultrastructural patterns, i.e., granular, curvilinear/rectilinear and fingerprint profiles. They contain−although to a different degree among the different CLN forms−subunit C of ATP synthase, saposins A and D, and beta-amyloid proteins. Extracerebral pathology, apart from lipopigment formation, which provides diagnostic information, is scant or non-existent. The retina undergoes atrophy in all childhood forms. While many new data and findings have been obtained by immunohistochemistry in mouse and other animal models, similar findings in human NCL are largely missing, thus recommending respective studies of archived brain tissues. The newly described NCL forms, i.e., CLN 10 to CLN 14, also require further studies to provide complete neuropathology. This article is part of a Special Issue entitled: “Current Research on the Neuronal Ceroid Lipofuscinoses (Batten Disease)”.

The autophagy-lysosomal pathway (ALP) regulates cell homeostasis and plays a crucial role in human diseases, such as lysosomal storage disorders (LSDs) and common neurodegenerative diseases. Therefore, the identification of DNA sequence variations in genes involved in this pathway and their association with human diseases would have a significant impact on health. To this aim, we developed Lysoplex, a targeted next-generation sequencing (NGS) approach, which allowed us to obtain a uniform and accurate coding sequence coverage of a comprehensive set of 891 genes involved in lysosomal, endocytic, and autophagic pathways. Lysoplex was successfully validated on 14 different types of LSDs and then used to analyze 48 mutation-unknown patients with a clinical phenotype of neuronal ceroid lipofuscinosis (NCL), a genetically heterogeneous subtype of LSD. Lysoplex allowed us to identify pathogenic mutations in 67% of patients, most of whom had been unsuccessfully analyzed by several sequencing approaches. In addition, in 3 patients, we found potential disease-causing variants in novel NCL candidate genes. We then compared the variant detection power of Lysoplex with data derived from public whole exome sequencing (WES) efforts. On average, a 50% higher number of validated amino acid changes and truncating variations per gene were identified. Overall, we identified 61 truncating sequence variations and 488 missense variations with a high probability to cause loss of function in a total of 316 genes. Interestingly, some loss-of-function variations of genes involved in the ALP pathway were found in homozygosity in the normal population, suggesting that their role is not essential. Thus, Lysoplex provided a comprehensive catalog of sequence variants in ALP genes and allows the assessment of their relevance in cell biology as well as their contribution to human disease.

The lysosome plays a pivotal role between catabolic and anabolic processes as the nexus for signalling pathways responsive to a variety of factors, such as growth, nutrient availability, energetic status and cellular stressors. Lysosomes are also the terminal degradative organelles for autophagy through which macromolecules and damaged cellular components and organelles are degraded. Autophagy acts as a cellular homeostatic pathway that is essential for organismal physiology. Decline in autophagy during ageing or in many diseases, including late-onset forms of neurodegeneration is considered a major contributing factor to the pathology. Multiple lines of evidence indicate that impairment in autophagy is also a central mechanism underlying several lysosomal storage disorders (LSDs). LSDs are a class of rare, inherited disorders whose histopathological hallmark is the accumulation of undegraded materials in the lysosomes due to abnormal lysosomal function. Inefficient degradative capability of the lysosomes has negative impact on the flux through the autophagic pathway, and therefore dysregulated autophagy in LSDs is emerging as a relevant disease mechanism. Pathology in the LSDs is generally early-onset, severe and life-limiting but current therapies are limited or absent; recognizing common autophagy defects in the LSDs raises new possibilities for therapy. In this review, we describe the mechanisms by which LSDs occur, focusing on perturbations in the autophagy pathway and present the latest data supporting the development of novel therapeutic approaches related to the modulation of autophagy.

Purpose: To analyze the clinical features, visual acuity, and full-field electroretinogram (ERG) findings of 15 patients with the neuronal ceroid lipofuscinosis (NCL) phenotype and to establish the role of ERG testing in NCL diagnosis. Methods: The medical records of five patients with infantile NCL, five with Jansky-Bielschowsky disease, and five with juvenile NCL who underwent full-field ERG testing were retrospectively analyzed. Results: Progressive vision loss was the initial symptom in 66.7% of patients and was isolated or associated with ataxia, epilepsy, and neurodevelopmental involution. Epilepsy was present in 93.3% of patients, of whom 86.6% presented with neurodevelopmental involution. Fundus findings ranged from normal to pigmentary/atrophic abnormalities. Cone-rod, rod-cone, and both types of dysfunction were observed in six, one, and eight patients, respectively. Conclusion: In our study, all patients with the NCL phenotype had abnormal ERG findings, and the majority exhibited both cone-rod and rod-cone dysfunction. We conclude that ERG is a valuable tool for the characterization of visual dysfunction in patients with the NCL phenotype and is useful for diagnosis. RESUMO Objetivo: Analisar o quadro clínico, a acuidade visual e o eletrorretinograma de campo total (ERG) de 15 pacientes com o fenótipo da lipofuscinose ceróide neuronal (LCN), estabelecendo o papel do eletrorretinograma no seu diagnóstico. Métodos: Eletrorretinograma foi realizado em 5 pacientes com lipofuscinose ceróide neuronal infantil, 5 com doença de Jansky-Bielschowsky e 5 com lipofuscinose ceróide neuronal juvenil sendo feita uma análise retrospectiva dos registros médicos. Resultados: A perda progressiva da acuidade visual foi o sintoma inicial em 66,7%; isolada ou associada à ataxia, epilepsia e involução do desenvolvimento neuropsico motor. Epilepsia foi o sintoma inicial em 93,3% e 86,6% apresentaram involução do desenvolvimento neuropsicomotor. Achados fundoscópicos variaram de normal a alterações pigmentares/atróficas. Disfunção de cone-bastonete foi constatada em 6 pacientes, bastonete-cone em 1 e em 8 pacientes observou-se disfunção proporcional de ambos os sistemas. Conclusão: O eletrorretinograma foi alterado em todos os pacientes, e o achado mais frequente foi o comprometimento de cones e bastonetes. O eletrorretinograma constitui, portanto, uma ferramenta valiosa para caracterizar a disfunção visual em pacientes com o fenótipo da lipofuscinose ceróide neuronal, contribuindo para seu diagnóstico.

The neuronal ceroid lipofuscinoses (NCLs, Batten disease) are inherited neurodegenerative lysosomal storage diseases caused by mutations in several different genes. Mutations in CLN5 cause a variant late-infantile human disease and some cases of juvenile and adult clinical disease. NCLs also occur in animals, and a flock of New Zealand Borderdale sheep with a CLN5 splice-site mutation has been developed for model studies. Dissociated mixed neural cells from CLN5-deficient foetal sheep brains contained no obvious storage bodies at plating but these accumulated rapidly in culture, mainly in microglial cells and also in neurons and astrocytes. Accumulation was very obvious after a week, as monitored by fluorescent microscopy and immunostaining for subunit c of mitochondrial ATP synthase. Photography at intervals revealed the dynamic nature of the cultures and a flow of storage bodies between cells, specifically the phagocytosis of storage-body containing cells by microglia and incorporation of the storage bodies into the host cells. No storage was observed in cultured control cells. Transduction of cell cultures with a lentiviral vector expressing a C-terminal Myc tagged CLN5 resulted in secretion of post-translationally glycosylated and processed CLN5. Transduction of CLN5-deficient cultures with this construct rapidly reversed storage body accumulation, to less than half in only six days. These results show that storage body accumulation is reversible with enzyme correction and support the use of these cultures for testing of therapeutics prior to whole animal studies.

Summary Neuronal ceroid lipofuscinoses, the most common fatal childhood neurodegenerative illnesses, share many features with more prevalent neurodegenerative diseases. Neuronal ceroid lipofuscinoses are caused by mutations in CLN genes. CLN6 encodes a transmembrane endoplasmic reticulum protein with no known function. We characterized the behavioural phenotype of spontaneous mutant mice modeling CLN6 disease, and demonstrate progressive motor and visual decline and reduced lifespan in these mice, consistent with symptoms observed in neuronal ceroid lipofuscinosis patients. Alterations to biometal homeostasis are known to play a critical role in pathology in Alzheimer's, Parkinson's, Huntington's and motor neuron diseases. We have previously shown accumulation of the biometals, zinc, copper, manganese and cobalt, in CLN6 Merino and South Hampshire sheep at the age of symptom onset. Here we determine the physiological and disease-associated expression of CLN6, demonstrating regional CLN6 transcript loss, and concurrent accumulation of the same biometals in the CNS and the heart of presymptomatic CLN6 mice. Furthermore, increased expression of the ER/Golgi-localized cation transporter protein, Zip7, was detected in cerebellar Purkinje cells and whole brain fractions. Purkinje cells not only control motor function, an early symptomatic change in the CLN6 mice, but also display prominent neuropathological changes in mouse models and patients with different forms of neuronal ceroid lipofuscinoses. Whole brain fractionation analysis revealed biometal accumulation in fractions expressing markers for ER, Golgi, endosomes and lysosomes of CLN6 brains. These data are consistent with a link between CLN6 expression and biometal homeostasis in CLN6 disease, and provide further support for altered cation transporter regulation as a key factor in neurodegeneration.

Neural stem/progenitor cells (NPCs) generate new neurons in the brain throughout an individual's lifetime in an intricate process called neurogenesis. Neurogenic alterations are a common feature of several adult-onset neurodegenerative diseases. The neuronal ceroid lipofuscinoses (NCLs) are the most common group of inherited neurodegenerative diseases that mainly affect children. Pathological features of the NCLs include accumulation of lysosomal storage material, neuroinflammation and neuronal degeneration, yet the exact cause of this group of diseases remains poorly understood. The function of the CLN5 protein, causative of the CLN5 disease form of NCL, is unknown. In the present study, we sought to examine neurogenesis in the neurodegenerative disorder caused by loss of Cln5. Our findings demonstrate a newly identified crucial role for CLN5 in neurogenesis. We report for the first time that neurogenesis is increased in Cln5-deficient mice, which model the childhood neurodegenerative disorder caused by loss of Cln5. Our results demonstrate that, in Cln5 deficiency, proliferation of NPCs is increased, NPC migration is reduced and NPC differentiation towards the neuronal lineage is increased concomitantly with functional alterations in the NPCs. Moreover, the observed impairment in neurogenesis is correlated with increased expression of the pro-inflammatory cytokine IL-1β. A full understanding of the pathological mechanisms that lead to disease and the function of the NCL proteins are critical for designing effective therapeutic approaches for this devastating neurodegenerative disorder., published version, peerReviewed

The neuronal ceroid lipofuscinoses (NCL) are a group of inherited, autosomal recessive, and progressive neurodegenerative diseases, which result from an enzymatic defect or the deficiency of a transmembrane protein, leading to the accumulation of lipopigments (lipofuscin) in various tissues. NCL results in the impairment of function in several end-organs including the central nervous system with loss of cognitive and motor function, myoclonus, and intractable seizures. Additional involvement includes the cardiovascular system with arrhythmias and bradycardia as well as impairment of thermoregulation leading to perioperative hypothermia. Given the complexity of the end-organ involvement and the progressive nature of the disorder, the anesthetic care of such patients can be challenging. Till date, there are a limited number of reports regarding the anesthetic management of patients with NCL. We present an 18-year-old patient with NCL who required anesthetic care during replacement of a vagal nerve stimulator. Previous reports of anesthetic care for these patients are reviewed, the end-organ involvement of NCL discussed, and options for anesthetic care presented.

Neuronal ceroid lipofuscinoses (NCL) are the most common inherited progressive encephalopathies of childhood. One of the most prevalent forms of NCL, Juvenile neuronal ceroid lipofuscinosis (JNCL) or CLN3 disease (OMIM: 204200), is caused by mutations in the CLN3 gene on chromosome 16p12.1. Despite progress in the NCL field, the primary function of ceroid-lipofuscinosis neuronal protein 3 (CLN3) remains elusive. In this study, we aimed to clarify the role of human CLN3 in the brain by identifying CLN3-associated proteins using a Tandem Affinity Purification coupled to Mass Spectrometry (TAP-MS) strategy combined with Significance Analysis of Interactome (SAINT). Human SH-SY5Y-NTAP-CLN3 stable cells were used to isolate native protein complexes for subsequent TAP-MS. Bioinformatic analyses of isolated complexes yielded 58 CLN3 interacting partners (IP) including 42 novel CLN3 IP, as well as 16 CLN3 high confidence interacting partners (HCIP) previously identified in another high-throughput study by Behrends et al., 2010. Moreover, 31 IP of ceroid-lipofuscinosis neuronal protein 5 (CLN5) were identified (18 of which were in common with the CLN3 bait). Our findings support previously suggested involvement of CLN3 in transmembrane transport, lipid homeostasis and neuronal excitability, as well as link it to G-protein signaling and protein folding/sorting in the ER.

The neuronal ceroid lipofuscinoses (NCLs) are lysosomal storage disorders and together are the most common degenerative brain diseases in childhood. They are a group of disorders linked by the characteristic accumulation of abnormal storage material in neurons and other cell types, and a degenerative disease course. All NCLs are characterized by a combination of dementia, epilepsy, and motor decline. For most childhood NCLs, a progressive visual failure is also a core feature. The characteristics of these symptoms can vary and the age at disease onset ranges from birth to young adulthood. Genetic heterogeneity, with fourteen identified NCL genes and wide phenotypic variability render diagnosis difficult. A new NCL classification system based on the affected gene and the age at disease onset allows a precise and practical delineation of an individual patient's NCL type. A diagnostic algorithm to identify each NCL form is presented here. Precise NCL diagnosis is essential not only for genetic counseling, but also for the optimal delivery of care and information sharing with the family and other caregivers. These aspects are challenging because there are also potential long term complications which are specific to NCL type. Therefore care supported by a specifically experienced team of clinicians is recommended. As the underlying pathophysiological mechanism is still unclear for all NCL forms, the development of curative therapies remains difficult. This article is part of a Special Issue entitled: The neuronal ceroid lipofuscinoses or Batten Disease.

CLN5 disease, late infantile variant phenotype neuronal ceroid lipofuscinosis, is a severe neurodegenerative disease caused by mutations in the CLN5 gene, which encodes a lysosomal protein of unknown function. Cln5-deficiency in mice leads to loss of thalamocortical neurons, and glial activation, but the underlying mechanisms are poorly understood. We have now studied the gene expression of Cln5 in the mouse brain and show that it increases gradually with age and differs between neurons and glia, with the highest expression in microglia. In Cln5(-/-) mice, we documented early and significant microglial activation that was already evident at 3 months of age. Loss of Cln5 also leads to defective myelination in vitro and in the developing mouse brain. This was accompanied by early alterations in serum lipid profiles, dysfunctional cellular metabolism and lipid transport in Cln5(-/-) mice. Taken together, these data provide significant new information about events associated with Cln5-deficiency, revealing altered myelination and disturbances in lipid metabolism, together with an early neuroimmune response.

Introduction The neuronal ceroid lipofuscinoses (NCLs; Batten disease) are a group of fatal neurodegenerative lysosomal storage diseases of children caused by various mutations in a range of genes. Forms associated with mutations in two of these, CLN5 and CLN6, are being investigated in well‐established sheep models. Brain atrophy leading to psychomotor degeneration is among the defining features, as is regional progressive ossification of the inner cranium. Ongoing viral‐mediated gene therapy trials in these sheep are yielding encouraging results. In vivo assessment of brain atrophy is integral to the longitudinal monitoring of individual animals and provides robust data for translation to treatments for humans. Methods Computed tomography (CT)‐based three‐dimensional reconstruction of the intracranial volume (ICV) over time reflects the progression of cortical brain atrophy, verifying the use of ICV measurements as a surrogate measure for brain size in ovine NCL. Results ICVs of NCL‐affected sheep increase for the first few months, but then decline progressively between 5 and 13 months in CLN5−/− sheep and 11–15 months in CLN6−/−sheep. Cerebral ventricular volumes are also increased in affected animals. To facilitate ICV measures, the radiodensities of ovine brain tissue and cerebrospinal fluid were identified. Ovine brain tissue exhibited a Hounsfield unit (HU) range of (24; 56) and cerebrospinal fluid a HU range of (−12; 23). Conclusions Computed tomography scanning and reconstruction verify that brain atrophy ovine CLN5 NCL originates in the occipital lobes with subsequent propagation throughout the whole cortex and these regional differences are reflected in the ICV loss.

Humoral autoimmunity against glutamic acid decarboxylase has been described in juvenile Batten disease patients and in the Cln3(-/-) mouse model. To obtain a more comprehensive understanding of the repertoire of antigens targeted, we examined the reactivity of Cln3(-/-) mouse sera to brain proteins from fetal, postnatal and adult rats. Among the candidate antigens identified was alpha-fetoprotein (AFP), a protein that has altered expression in several nervous system disorders and hepatic malignancies. Moreover, AFP levels were upregulated in the brains and livers of postnatal day 14 Cln3(-/-) animals. Sera from 31 juvenile Batten disease patients revealed the presence of anti-AFP autoantibodies in juvenile Batten disease male patients (12/13) and female patients (8/18). While these findings provide more evidence that autoimmunity is an active component of juvenile Batten disease, the gender-apparent difference evidenced by patients with regard anti-AFP antibodies may underlie variation in progression and clinical manifestations in this disorder.

Patients and a mouse model of Batten disease, the juvenile form of neuronal ceroid lipofuscinosis (JNCL), raise autoantibodies against GAD65 and other brain-directed antigens. Here we investigate the adaptive component of the neuroimmune response. Cln3(-/-) mice have autoantibodies to GAD65 in their cerebrospinal fluid and elevated levels of brain bound immunoglobulin G (IgG). IgG deposition was found within human JNCL autopsy material, a feature that became more evident with increased age in Cln3(-/-) mice. The lymphocyte infiltration present in human and murine JNCL occurred late in disease progression, and was not capable of central/intrathecal IgG production. In contrast, we found evidence for an early systemic immune dysregulation in Cln3(-/-) mice. In addition evidence for a size-selective breach in the blood-brain barrier integrity in these mice suggests that systemically produced autoantibodies can access the JNCL central nervous system and contribute to a progressive inflammatory response.

AimsSynapses represent a major pathological target across a broad range of neurodegenerative conditions. Recent studies addressing molecular mechanisms regulating synaptic vulnerability and degeneration have relied heavily on invertebrate and mouse models. Whether similar molecular neuropathological changes underpin synaptic breakdown in large animal models and in human patients with neurodegenerative disease remains unclear. We therefore investigated whether molecular regulators of synaptic pathophysiology, previously identified in Drosophila and mouse models, are similarly present and modified in the brain of sheep with CLN5 Batten disease.MethodsGross neuropathological analysis of CLN5 Batten disease sheep and controls was used alongside postmortem MRI imaging to identify affected brain regions. Synaptosome preparations were then generated and quantitative fluorescent Western blotting used to determine and compare levels of synaptic proteins.ResultsThe cortex was particularly affected by regional neurodegeneration and synaptic loss in CLN5 sheep, whilst the cerebellum was relatively spared. Quantitative assessment of the protein content of synaptosome preparations revealed significant changes in levels of seven out of eight synaptic neurodegeneration proteins investigated in the motor cortex, but not cerebellum, of CLN5 sheep (α-synuclein, CSP-α, neurofascin, ROCK2, calretinin, SIRT2, and UBR4).ConclusionsSynaptic pathology is a robust correlate of region-specific neurodegeneration in the brain of CLN5 sheep, driven by molecular pathways similar to those reported in Drosophila and rodent models. Thus, large animal models, such as sheep, represent ideal translational systems to develop and test therapeutics aimed at delaying or halting synaptic pathology for a range of human neurodegenerative conditions.