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Brain monoamine vesicular transport disease is an infantile-onset movement disorder that mimics cerebral palsy. In 2013, the homozygous SLC18A2variant, p.Pro387Leu, was first reported as a cause of this rare disorder, and dopamine agonists were efficient for treating affected individuals from a single large family. To date, only 6 variants have been reported. In this study, we evaluated genotype–phenotype correlations in individuals with biallelic SLC18A2variants.

Background: The trafficking protein particle (TRAPP) complex subunit 9 (C9) protein is a member of TRAPP-II complexes and regulates vesicle trafficking. Biallelic mutations in the TRAPPC9gene are responsible for intellectual disability with expanded developmental delay, epilepsy, microcephaly, and brain atrophy. TRAPPC9-related disease list is still expanding, however, the functional effects of only a limited fraction of these have been studied. Methods: In a patient with a pathological variant in TRAPPC9, clinical examination and cranial imaging findings were evaluated. Whole-exome sequencing, followed by Sanger sequencing was performed to detect and verify the variant. To confirm the functional effect of the mutation; variant mRNA and protein expression levels were evaluated by qRT-PCR and Western blotting. Immunostaining for TRAPPC9 and lipid droplet accumulation were examined. Results: We have identified a novel homozygous c.696C>G (p.Phe232Leu) pathogenic variant in TRAPPC9(NM_031466.6) gene as a cause of severe developmental delay. Functional characterization of the TRAPPC9variant resulted in decreased mRNA and protein expression. The intracellular findings showed that TRAPPC9 protein build-up around the nucleus in mutant type while there was no specific accumulation in the control cell line. This disrupted protein pattern affected the amount of neutral lipid-carrying vesicles and their homogenous distribution at a decreasing level. Conclusion: Biallelic variants in the TRAPPC9gene have been reported as the underlying cause of intellectual disability. This study provides functional evidence of the novel variant in TRAPPC9We demonstrated that the loss of function variant exclusively targeting TRAPPC9may explicate the neurological findings through vesicle trafficking.

Previously we reported the identification of a homozygous COL27A1(c.2089G>C; p.Gly697Arg) missense variant and proposed it as a founder allele in Puerto Rico segregating with Steel syndrome (STLS, MIM #615155); a rare osteochondrodysplasia characterized by short stature, congenital bilateral hip dysplasia, carpal coalitions, and scoliosis. We now report segregation of this variant in five probands from the initial clinical report defining the syndrome and an additional family of Puerto Rican descent with multiple affected adult individuals. We modeled the orthologous variant in murine Col27a1and found it recapitulates some of the major Steel syndrome associated skeletal features including reduced body length, scoliosis, and a more rounded skull shape. Characterization of the in vivo murine model shows abnormal collagen deposition in the extracellular matrix and disorganization of the proliferative zone of the growth plate. We report additional COL27A1pathogenic variant alleles identified in unrelated consanguineous Turkish kindreds suggesting Clan Genomics and identity-by-descent homozygosity contributing to disease in this population. The hypothesis that carrier states for this autosomal recessive osteochondrodysplasia may contribute to common complex traits is further explored in a large clinical population cohort. Our findings augment our understanding of COL27A1biology and its role in skeletal development; and expand the functional allelic architecture in this gene underlying both rare and common disease phenotypes.

Background: Autism Spectrum Disorder (ASD) is a complex developmental disorder in which neurological basis is largely unknown. The Corpus Callosum (CC) is the main commissure that connects the cerebral hemispheres. Previous evidence suggests the involvement of the CC in the pathophysiology of autism. Aim: The aim of our study is to assess whether there were any changes in Corpus Callosum (CC) area and volume and to reveal the relationship between Diffusion Tensor Imaging (DTI) features in genu and splenium of corpus callosum in children with ASD. Methods: Eighteen patient and 15 controls were recruited. The volumetric sagittal TI images were used to provide measurements of midsagittal corpus callosum surface area while FA, MD, RD, and ADC values were extracted from genu and splenium of corpus callosum after which the correlation in the area and volume in ASD children was examined. Results: CC area and volume in children with ASD were decreased than controls. FA values obtained from the genu and splenum of CC were significantly lower and RD values were significantly higher. A positive correlation was observed between the FA of the genu and splenium and area and volume of the CC. There was a negative correlation between ADC, MD and RD of CC and area and volume measurements. Conclusion: The conclusions in the interrelations of morphometric and DTI data may demonstrate a likelihood of damages in the axons and cortical neurons. The results showed that there existed microstructural damages from the DTI findings. Furthermore, the decrease in FA could be a representation of the reduction in the myelination in nerve pathways, impaired integrity, reduced axonal density, and organization. Indeed, the changes in volumetric and microstructural of CC could be useful in evaluating underlying pathophysiology in children with autism.

Cerebrotendinous xanthomatosis (CTX) is a lipid storage disorder caused by defective sterol 27-hydroxylase activity. In spite of subtle clinical signs beginning from childhood, CTX is generally diagnosed lately. The aim of this study is to evaluate clinical, neuroradiological findings and therapy responses of pediatric CTX patients and raise awareness to early features of disease. Patients who were molecularly diagnosed as CTX before 18 years of age were included in study. Clinical, epidemiological, radiological and genotypic features of patients and chenodeoxycholic acid (CDCA) therapy responses were reviewed retrospectively. Six patients were enrolled in the study. The mean age of diagnosis was 11.1 ± 4.5 years. Apart from previous studies, predominance of cerebellar signs over pyramidal signs, peripheral neuropathy with demyelinating neuropathy in majority of patients and pathological brain imaging findings despite young ages of patients were observed. Intention tremor was the consisting finding of all patients. Optic disc drusen was initially reported in one patient. Skeletal system involvement as coarse extremities, deformities and early osteoporosis was recognized in four patients. CDCA therapy improved or at least stabilized neurological functions in all patients. This study is the first CTX series from Turkey and performed among only in early diagnosed patients with a therapy follow-up contrary to limited data in the literature. We suggest that, awareness of intention tremor and ataxic gait in addition to mental retardation, peripheral neuropathy and early osteoporosis can be suspicious for CTX and lead diagnosis. Early treatment can provide stability and may also ameliorate existing neurological findings.

Primary ovarian insufficiency (POI) encompasses a spectrum of premature menopause, including both primary and secondary amenorrhea. For 75% to 90% of individuals with hypergonadotropic hypogonadism presenting as POI, the molecular etiology is unknown. Common etiologies include chromosomal abnormalities, environmental factors, and congenital disorders affecting ovarian development and function, as well as syndromic and nonsyndromic single gene disorders suggesting POI represents a complex trait.

Biallelic mutations in the TBX19gene cause severe early-onset adrenal failure due to isolated ACTH deficiency (IAD). This rare disease is characterized by low plasma ACTH and cortisol levels, with normal secretion of other pituitary hormones. Herein, we report a patient with IAD due to a novel TBX19gene mutation, who is also of tall stature. A 48/12-year-old girl was presented with loss of consciousness due to hypoglycemia. The patient was born at term with a birth weight of 3800 g. Her parents were first-degree cousins. She had a history of several hospitalizations for recurrent seizures, abdominal pain, and vomiting. At presentation, her weight and height were + 1.8 and + 2.2 SDS, respectively. Serum glucose was 25 mg/dl (1.4 mmol/L), with normal sodium, potassium, and insulin concentrations. The child was hypocortisolemic (0.1 μg/dl), and ACTH levels were extremely low (< 5.0 pg/ml). A diagnosis of IAD was made and hydrocortisone treatment was started. Hypoglycemic episodes, seizures, and recurrent gastrointestinal complaints disappeared after hydrocortisone replacement. Magnetic resonance imaging of the pituitary was normal. Whole exome sequencing revealed a novel homozygous c.302G > A (W101*) mutation in the TBX19gene. We report a new mutation in the TBX19gene in a patient with isolated ACTH deficiency. While overgrowth is a known feature of some types of adrenal insufficiencies, including MC2Rgene defects and POMC deficiency, it may be a novel feature for TPIT deficiency, as in our patient.

Multilocus variation—pathogenic variants in two or more disease genes—can potentially explain the underlying genetic basis for apparent phenotypic expansion in cases for which the observed clinical features extend beyond those reported in association with a “known” disease gene.

Background: In spite of the fact that advanced neuroimaging applications are used for the evaluation of Tuberous Sclerosis (TS) patients, a few studies analyzed relationship between the measurements of DTI (diffusion tensor imaging) and neurological findings. Objectives: Evaluate DTI properties of cortical tubers and white matter lesions in TS, and analyze whether there was a correlation between DTI findings and neurological findings. Materials and Methods: MRI and DTI were performed on 31 subjects with TS. DTI findings of subjects with TS were compared with those of the control group. Then, the correlation between DTI values and neurological findings was analyzed. Results: ADC values of cortical tubers and white matter lesions in subjects with epilepsy were higher than in those without epilepsy. Additionally, the MRI lesion scores showed that our subjects with epilepsy had more lesions than without epilepsy. Conclusions: DTI findings of cortical tubers and white matter lesions in TS subjects could be related to microstructural changes such as neuronal loss and the impairment of myelin integrity. We hypothesized that severity neurological symptoms may be correlated with MRI lesion load and DTI parameters.

Context:Hypergonadotropic hypogonadism presents in females with delayed or arrested puberty, primary or secondary amenorrhea due to gonadal dysfunction, and is further characterized by elevated gonadotropins and low sex steroids. Chromosomal aberrations and various specific gene defects can lead to hypergonadotropic hypogonadism. Responsible genes include those with roles in gonadal development or maintenance, sex steroid synthesis, or end-organ resistance to gonadotropins. Identification of novel causative genes in this disorder will contribute to our understanding of the regulation of human reproductive function.Objectives:The aim of this study was to identify and report the gene responsible for autosomal-recessive hypergonadotropic hypogonadism in two unrelated families.Design and Participants:Clinical evaluation and whole-exome sequencing were performed in two pairs of sisters with nonsyndromic hypergonadotropic hypogonadism from two unrelated families.Results:Exome sequencing analysis revealed two different truncating mutations in the same gene: SOHLH1c.705delT (p.Pro235fs*4) and SOHLH1c.27C>G (p.Tyr9stop). Both mutations were unique to the families and segregation was consistent with Mendelian expectations for an autosomal-recessive mode of inheritance.Conclusions:Sohlh1was known from previous mouse studies to be a transcriptional regulator that functions in the maintenance and survival of primordial ovarian follicles, but loss-of-function mutations in human females have not been reported. Our results provide evidence that homozygous-truncating mutations in SOHLH1cause female nonsyndromic hypergonadotropic hypogonadism.