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Összefoglaló. A fejlett társadalmak egészségügyi rendszereinek legnagyobb kihívását az öregedéssel összefüggő, korfüggő betegségek jelentik. Annak megértéséhez, hogy az egyes genetikai variánsoknak mi a szerepük egy korfüggő betegség kialakulásában, meg kell ismerkednünk magával az öregedési folyamattal, az egészséges hosszú élettel asszociált, valamint az adott populációra jellegzetes variánsokkal is. A Semmelweis Egyetem Genomikai Medicina és Ritka Betegségek Intézete a Nemzeti Bionika Program keretén belül a Magyar Genomikai Egészségtárház felállítását tűzte ki célul, időskoruk mellett is egészséges önkéntesek teljesgenom-szekvenciáinak és kapcsolódó fenotípusadatainak katalogizálásával és elemzésével, létrehozva az első magyar teljes genomi referencia-adatbázist. Fontos szempont volt, hogy a kutatás az egészséges öregedést vizsgáló nemzetközi projektekhez is kapcsolódást biztosítson, így lehetőséget teremtve a különböző országokból származó adatok harmonizálására és közös elemzésére. A kutatás résztvevőinek 49%-a 70–80 éves, 36%-a 81–90 éves, 14%-uk pedig 90 év feletti; a nemek aránya 44/56%-os megoszlást mutatott a férfiak és a nők között. A résztvevők csaknem fele (46%) egyedül él. Magas a felsőfokú végzettségűek aránya (46%), a résztvevők 61%-a hosszú időn át sportolt, 70%-uk sosem dohányzott. A vizsgálati alanyok szülei is magas életkort éltek meg, az édesapáknál 74,3, az édesanyák esetében pedig 80,47 év volt a halálozáskori átlagéletkor. Adattárházunk elsőként tervez hozzáférést biztosítani egy magyar teljes genomi referencia-adatbázishoz, amely a genetikusan meghatározott betegségek és fenotípusok kutatásában és a klinikai gyakorlatban is alapvető fontosságú. A projekt bioinformatikai fejlesztései a genetikai/genomikai információk többszintű elérését támogatják a személyes adatok védettségét megőrző statisztikai elemzési és mesterségesintelligencia-eljárások segítségével. Orv Hetil. 2021; 162(27): 1079–1088. Summary. Genetics has proven to be a a successful approach in the study of ageing. To understand the role of each genetic variant in the development of an age-dependent disease, we need to become familiar with the ageing process itself and with the population-specific variants. The Institute of Genomic Medicine and Rare Disorders of the Semmelweis University within the framework of the National Bionics Program set up a data collection, the Hungarian Genomic Data Warehouse, by cataloging and analyzing complete genome sequences and related phenotype data of healthy volunteers, which also serves as a reference national Hungarian genomic database. The structure of the data warehouse allows interoperability with the most important international research projects on ageing. 49% of the participants in the Hungarian Genomic Data Warehouse were 70–80 years old, 36% were 81–90, 14% over 90 years old. The gender ratio was 44/56% between men and women. The proportion of people with higher education is high (46%), 61% of the participants played sports for a long time, and 70% never smoked. The parents of the participants also lived a high age, with an average age at death of 74.3 years for fathers and 80.47 years for mothers. The Hungarian Genomic Data Warehouse can provide vital and timely support in personalized medicine, especially in the research and diagnosis of genetically inherited disorders. The long-term goal of these bioinformatic developments is to provide access at multiple levels to the genomic data using privacy-preserving data analysis methods in genomics. Orv Hetil. 2021; 162(27): 1079–1088.

Absztrakt: A nukleárisan kódolt POLG-gén fehérjeterméke kulcsszerepet játszik a mitokondriális DNS replikációjának fenntartásában, és hibája különböző súlyosságú, több szervrendszert érintő betegségeket okoz. A klinikai spektrum rendkívül tág, a leggyakrabban előforduló tünetek közé tartozik többek között a ptosis, a myoclonus, az epilepszia, a myopathia, a szenzoros ataxia, a parkinsonizmus, a kognitív hanyatlás és az infertilitás is. Ma már ismert, hogy a Parkinson-kór kialakulása során a mitokondriális diszfunkció is nagy jelentőséggel bír a substantia nigra dopaminerg sejtjeinek elhalásában. Ezért a POLG-génben bekövetkező változások befolyásolhatják a különböző örökletes neurodegeneratív betegségeknek, így a monogénes parkinsonizmusnak a kialakulását is. A Parkinson-kór és a POLG kapcsolatáról azonban még kevés az elérhető információ, és ez idáig a magyar populációra vonatkozó adatok sem álltak rendelkezésünkre. Vizsgálatunk során 67 magyar, a parkinsonizmus tüneteit mutató páciens esetében újgenerációs szekvenálást végeztünk, és a POLG-génben található, potenciálisan káros variánsokat elemeztük. 3 beteg esetében azonosítottunk potenciálisan kóroki eltérést. Közleményünkkel arra szeretnénk felhívni a figyelmet, hogy a parkinsonizmus differenciáldiagnózisa során az esetleges POLG genetikai érintettségét is figyelembe kell venni. Különösen olyan plusztünetek jelenlétekor, mint az ophthalmoparesis, a nem vascularis típusú fehérállományi laesiók, a pszichiátriai komorbiditás és a tünetek viszonylag korai indulása. Korábbi irodalmi adatok és saját tapasztalataink alapján összefoglaltuk a POLG-asszociált parkinsonizmus lehetséges diagnosztikai megközelítését is. Orv Hetil. 2020; 161(20): 821–828.

Pompe disease (PD) is a rare lysosomal disease caused by the deficient activity of acid alpha-glucosidase (GAA) enzyme due to mutations in the GAA gene. The enzymatic deficiency leads to the accumulation of glycogen within the lysosomes. Clinically, the disease has been classically classified in infantile and childhood/adult forms. Presently cc. close to 600 mutations distributed throughout the whole gene have been reported. The c.-32-13T>G splice mutation that is very common in patients of Caucasian origin affected by the childhood/adult form of the disease, with an allelic frequency close to 70%. Enzyme replacement treatment (ERT) is available for the patients with Pompe disease (Myozyme). In this paper, we are presenting the long term follow up of 13 adult onset cases treated more than 5 years. The longest follow up was 15 years. To evaluate the treatment efficacy, the 6 minutes walking test (6MWT) and the respiratory functions were monitored annually. The analysis revealed that at the beginning of ERT for 3-4 years the 6MWT had been generally increasing, then it declined, and after 10 years it was lower in 77% of the cases than it had been at the start of the treatment. In 23% of the cases the 6MWT increased during the follow up time. Only one of the patients become wheelchair dependent during the follow-up period. The respiratory function showed similar results especially in supine position. A high degree of variability was observed among patients in their responses to the treatment, which only partially associated with the antibody titer against the therapeutic protein. The efficacy of the ERT was associated with the type of the disease causing mutation, the baseline status of the disease, the lifestyle and the diet of the patient. The long-term follow up of the patients with innovative orphan drugs is necessary to really understand the value of the treatment and the need of the patients.

Background Perrault syndrome is a genetically heterogenous, very rare disease, characterized clinically by sensorineural hearing loss, ovarian dysfunction and neurological symptoms. We present the case of a 33 years old female patient with TWNK-associated Perrault syndrome. The TWNK gene is coding the mitochondrial protein Twinkle and currently there are only two reports characterizing the phenotype of TWNK-associated Perrault syndrome. None of these publications reported about special brain MRI alterations and neuropathological changes in the muscle and peripheral nerves. Case presentation Our patients with TWNK-dependent Perrault syndrome had severe bilateral hypoacusis, severe ataxia, polyneuropathy, lower limb spastic paraparesis with pyramidal signs, and gonadal dysgenesis. Psychiatric symptoms such as depression and paranoia were present as well. Brain MRI observed progressive cerebellar hyperintensive signs associated with cerebellar, medulla oblongata and cervical spinal cord atrophy. Light microscopy of the muscle biopsy detected severe neurogenic lesions. COX staining was centrally reduced in many muscle fibers. Both muscle and sural nerve electron microscopy detected slightly enlarged mitochondria with abnormal cristae surrounded by lipid vacuoles. In the sural nerve, dystrophic axons had focally uncompacted myelin lamellae present. Genetic investigation revealed multiple mtDNA deletion and compound heterozygous mutations of the TWNK gene (c.1196 A > G, c.1358 G > A). Conclusion This study demonstrates that TWNK associated Perrault syndrome has a much broader phenotype as originally published. The coexistence of severe hypoacusis, spastic limb weakness, ataxia, polyneuropathy, gonadal dysgensia, hyperintense signals in the cerebellum and the presence of the mtDNA multiple deletion could indicate the impairment of the TWNK gene. This is the first report about pyramidal tract involvement and cerebellar MRI alteration associated with TWNK-related Perrault syndrome.

In this letter-to-the-editor the Task Force on Gender and Diversity issues in Neurology founded under the auspices of the European Academy of Neurology (EAN) addresses various gender issues that are arising during the COVID-19 pandemic. These issues concern different aspects, spanning from gender disparities in health care workforce to gender differences amongst patients suffering from COVID-19, risk factors, occurrence of neurological complications and (outcomes of) management. Due to the continuous flow of COVID-19 related papers this review cannot be comprehensive. We attempted to select the most relevant literature on this topic.

IntroductionPhospholipase A2-associated Neurodegeneration (PLAN) is a group of neurodegenerative diseases associated with the alterations of PLA2G6. Some phenotype-genotype association are well known but there is no clear explanation why some cases can be classified into distinct subgroups, while others follow a continuous clinical spectrum.MethodsLong-term neurological, and psychiatric follow-up, neuropathological, radiological, and genetic examinations, were performed in three affected girls and their family.ResultsTwo 24-years old twins and their 22-years old sister harbored the p.P622S, and p.R600W mutation in PLA2G6. The age of onset and the most prominent presenting symptoms (gaze palsy, ataxia, dystonia, psychomotor regression indicated atypical neuroaxonal dystrophy (ANAD), however, optic atrophy, severe tetraparesis would fit into infantile neuroaxonal dystrophy (INAD). All siblings had hyperintensity in the globi pallidi and substantiae nigrae which is reported in ANAD, whereas it is considered a later neuroradiological marker in INAD. The slow progression, rigidity, bradykinesis, and the prominent psychiatric symptoms indicate PLA2G6-related dystonia-parkinsonism. Abnormal mitochondria, lipid accumulation and axonal spheroids were observed in the muscle and nerve tissue. Brain deposition appeared 6 years following the initial cerebellar atrophy. Mild MRI alterations were detected in the asymptomatic carrier parents.ConclusionThe colorful clinical symptoms, the slightly discordant phenotype, and the neuroimaging data in the family supports the view that despite the distinct definition of age-related phenotypes in PLAN, these are not strict disease categories, but rather a continuous phenotypic spectrum. The mild MRI alterations of the parents and the family history suggest that even heterozygous pathogenic variants might be associated with clinical symptoms, although systematic study is needed to prove this.

Abstract: Introduction: Congenital sensorineural hearing loss is one of the most common sensory defects affecting 1–3 children per 1000 newborns. There are a lot of causes which result in congenital hearing loss, the most common is the genetic origin, but infection, cochlear malformation or other acquired causes can be reasons as well. Aim: The aim of this study was to establish the etiological factors of congenital profound sensorineural hearing loss in children who underwent cochlear implantation. Results: Our results show that the origin of the hearing loss was discovered in 62.9% of our patients. The most common etiological factor was the c.35delG mutation of the gap junction protein β-2 gene, the allele frequency was 38.7% in our cohort. Infection constituted to 10.1%, and meningitis and cytomegalovirus infection were the second most common cause. 79.9% of our patients received sufficient hearing rehabilitation before the end of the speech development’s period (6 years old), but 11.2% of our cases were still diagnosed late. Conclusions: Based on our data we can state that genetic evaluation is crucial in the diagnostic process of congenital profound sensorineural hearing loss. Sufficient hearing rehabilitation affects the whole life of the child, and by late cochlear implantation the speech development falls behind. We can decrease the ratio of the late implantation with the new protocol of newborn hearing screening, and with sufficient information provided to the colleagues, so the children may be referred to the proper center for rehabilitation without delay. Orv Hetil. 2019; 160(21): 822–828.

Pompe disease is caused by the accumulation of glycogen in the lysosomes due to a deficiency of the lysosomal acid-α-glucosidase (GAA) enzyme. Depending on residual enzyme activity, the disease manifests two distinct phenotypes. In this study, we assess an enzymatic and genetic analysis of Hungarian patients with Pompe disease. Twenty-four patients diagnosed with Pompe disease were included. Enzyme activity of acid-α-glucosidase was measured by mass spectrometry. Sanger sequencing and an MLPA of the GAA gene were performed in all patients. Twenty (83.33%) patients were classified as having late-onset Pompe disease and four (16.66%) had infantile-onset Pompe disease. Fifteen different pathogenic GAA variants were detected. The most common finding was the c.-32-13 T &gt, G splice site alteration. Comparing the α-glucosidase enzyme activity of homozygous cases to the compound heterozygous cases of the c.-32-13 T &gt, G disease-causing variant, the mean GAA activity in homozygous cases was significantly higher. The lowest enzyme activity was found in cases where the c.-32-13 T &gt, G variant was not present. The localization of the identified sequence variations in regions encoding the crucial protein domains of GAA correlates with severe effects on enzyme activity. A better understanding of the impact of pathogenic gene variations may help earlier initiation of enzyme replacement therapy (ERT) if subtle symptoms occur. Further information on the effect of GAA gene variation on the efficacy of treatment and the extent of immune response to ERT would be of importance for optimal disease management and designing effective treatment plans.

Introduction Rhabdomyolysis is a syndrome characterized by a rapid necrosis of muscle fibers and the release of muscle-derived metabolic products into the circulatory system. A rare cause of rhabdomyolysis is paraneoplastic polymyositis. Case presentation A 67-year-old man was diagnosed with paraneoplastic polymyositis and rhabdomyolysis caused by hepatocellular carcinoma (HCC). Intravenous steroid was used as a symptomatic therapy for rhabdomyolysis, and the tumour was removed by left hemihepatectomy to treat the underlying cause. After muscle strength gradually improved, steroid therapy was discontinued. The patient was reoperated multiple times due to bleeding and bile leakage. Following the operations, his overall state and muscle strength further improved. Despite that, the patient's condition worsened again, and eventually, he died of candida albicans pneumonia and sepsis. Discussion HCC is an extremely rare cause of paraneoplastic polymyositis and rhabdomyolysis. Treatment is challenging, as none of the few available case reports record long term survival and less than half of the reports record muscle strength improvement. In our case, the patient was treated with systemic steroid therapy and resection of the tumour. The patient's muscle strength temporarily improved, but subsequently, the patient died. Conclusion Our case confirms the importance of a definitive treatment of HCC, as we achieved a significant improvement in muscle strength by removing the tumour. On the other hand, our paper highlights the dangers of double-sided steroid therapy, which, combined with the essential, effective treatment of rhabdomyolysis, may have contributed to the development of postoperative complications and candida sepsis leading to death., Highlights • Hepatocellular carcinoma is an extremely rare cause of paraneoplastic polymyositis. • Definitive treatment of paraneoplastic polymyositis is surgical removal of the tumour. • Steroid therapy is an essential treatment of polymyositis and rhabdomyolysis. • Steroid therapy also increases the risk of postoperative complications. • Steroid therapy, combined with surgical treatment may lead to increased postoperative risk.

There is increasing evidence that several mitochondrial abnormalities are present in the brains of patients with Alzheimer’s disease (AD). Decreased alpha-ketoglutarate dehydrogenase complex (αKGDHc) activity was identified in some patients with AD. The αKGDHc is a key enzyme in the Krebs cycle. This enzyme is very sensitive to the harmful effect of reactive oxygen species, which gives them a critical role in the Alzheimer and mitochondrial disease research area. Previously, several genetic risk factors were described in association with AD. Our aim was to analyze the associations of rare damaging variants in the genes encoding αKGDHc subunits and AD. The three genes (OGDH, DLST, DLD) encoding αKGDHc subunits were sequenced from different brain regions of 11 patients with histologically confirmed AD and the blood of further 35 AD patients. As a control group, we screened 134 persons with whole-exome sequencing. In all subunits, a one–one rare variant was identified with unknown significance based on American College of Medical Genetics and Genomics (ACMG) classification. Based on the literature research and our experience, R263H mutation in the DLD gene seems likely to be pathogenic. In the different cerebral areas, the αKGDHc mutational profile was the same, indicating the presence of germline variants. We hypothesize that the heterozygous missense R263H in the DLD gene may have a role in AD as a mild genetic risk factor.

BackgroundMarfan syndrome (MFS) is a systemic connective tissue disorder with life-threatening manifestations affecting the ascending aorta. MFS is caused by dominant negative (DN) and haploinsufficient (HI) mutations of theFBN1gene. Our aim was to identify mutations of MFS patients with high detection rate and to investigate the use of a gene panel for patients with Marfanoid habitus. We also aimed to examine correlations between genotype and cardiovascular manifestations to predict “malignant” mutations.Methods136 individuals were enrolled. In the first phase, next-generation sequencing (NGS) and Sanger sequencing were performed for 57 patients to screen theFBN1gene, followed by multiplex ligation-dependent probe amplification (MLPA) in negative cases. For repeated negative results, NGS gene panel involving 9 genes was used. In the second phase, 79 patients were tested primarily with the same gene panel, negative samples were tested by MLPA.Results84 pathogenic mutations were detected, out of which 78 affectedFBN1, 6 non-FBN1mutations (2TGFB2, 1TGFBR2, 2TGFBR1, 1SMAD3) are associated with Loeys-Dietz syndrome (LDS). LDS patients had lower systemic score and they were younger, but their aortic involvement did not differ. MLPA detected 4 multi-exon deletions ofFBN1gene, which could not be identified by our first-step screening method. Aortic involvement (aortic dissection and/or dilation) did not differ significantly among HI and DN mutations (p = 0.061). Combined group of HI and DN mutations eliminating a disulphide-bonding cysteine (DN Cys) had significantly higher aortic involvement rate than DN mutations not eliminating a disulphide-bonding cysteine (DN non-Cys) (p p = 0.042 andp = 0.015, respectively).ConclusionsDue to the relevant number of mutations affecting genes other thanFBN1, preferred approach for testing individuals with Marfanoid habitus is using a gene panel rather than single-gene analysis, followed by MLPA for negative samples. DN Cys and HI mutations should be considered as risk factors for aortic involvement. Genetic testing for patients with Marfanoid features and a systemic score under 7 is recommended, as LDS patients may have lower scores, but they may have severe cardiovascular manifestations.

Schizophrenia is a chronic and severe mental disorder characterized by positive, negative, and cognitive symptoms. Negative symptoms are usually present from the prodromal phase; early diagnosis and management of negative symptoms is a major health concern since an insidious onset dominated by negative symptoms is associated with a worse outcome. Antipsychotic medications, which are effective for treating positive symptoms, are generally ineffective for treating negative or cognitive symptoms. We present a 23-year-old woman showing severe symptoms at her first visit to our department. The patient’s parents reported that their daughter had experienced several years of psychosocial decline and putative psychiatric symptoms, but no medical attention had been previously sought; as such, the diagnosis of schizophrenia with predominantly negative symptoms was very much delayed. Early onset of schizophrenia, longer duration of untreated psychosis, and severe negative symptoms, which have limited treatment options, suggested a poor prognosis. We initiated monotherapy with cariprazine, a novel antipsychotic that has recently been proven efficacious in treating schizophrenia with predominantly negative symptoms. This report describes a 52-week cariprazine treatment regimen and follows the patient’s impressive clinical improvement confirmed by PANSS and CGI scores, and psychological tests.

Introduction Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by a homozygous deletion of the survival motor neuron (SMN) 1 gene. Nusinersen is an antisense oligonucleotide enhancing the production of the SMN protein. It has received approval by the European Medicines Agency (EMA) in 2017, based on the clinical trials demonstrating the effectiveness of nusinersen in several types of SMA. In Hungary, the first patient received nusinersen treatment in April 2018. Our aim is to summarize our experience regarding the efficacy, safety and tolerability of nusinersen in our patients. Methods Data were collected retrospectively in all types of SMA patients (type 1–3) starting treatment with nusinersen in Hungary between April 2018 and December 2019. Motor functions were evaluated at baseline, at the fourth and all following injections. Results By 31st December 2019, nusinersen therapy was initiated in 54 patients at either of the two Hungarian treatment centres. Mean age of the patients at the start of the treatment was 6.3 years (±5,4 range 0.4–17.9). 13 patients are type 1 (mean 0.78 ± 0.27, range 0.4–1.5 yrs), 21 patients are type 2 (mean 4.5 ± 3.3, range 1.3–12 yrs), 23 patients are type 3 (mean 10.9 ± 5.2, range 2.9–17.9 yrs). Fourteen patients had severe scoliosis, four of them underwent spine stabilizing surgery. During the study period 340 injections were administered without any new safety concerns emerging. The data of 38 patients, who had completed the first six treatments, were included in the final statistical analysis. Motor function has improved in most of the children. By the 307th day visit, on average, a 14.9 (±5,1) point improvement was measured on the CHOP INTEND scale in type 1 patients (p = 0.016). All patients with type 1 SMA who performed the motor evaluation (7/10) have improved by more than four (7-21) points. Regarding type 2 patients, a 7.2 (range -2- 17) point increase from baseline (p Conclusion According to our results nusinersen has the same safety and tolerability profile as in the clinical trials. In a heterogenic patient population of SMA type 1 and 2, nusinersen showed similar efficacy as seen in the pivotal studies. A clinically and statistically significant improvement of motor functions was also detectable in type 3 patients with heterogeneous age distribution.

Abstract: Next generation sequencing (NGS) technologies reshape the diagnostics of rare neurological diseases. In the background of certain neurological symptoms, such as ataxia, many acquired and genetic causes may be present. Variations in a given gene can present with variable phenotypes, too. Because of this phenomenon, the conventional one gene sequencing approach often fails to identify the genetic background of a disease. Next generation sequencing panels allow to sequence 50–100 genes simultaneously, and if the disease stratification is not possible based on the clinical symptoms, whole exome sequencing can help in the diagnostic of genetic disorders with atypical presentation. This case study is about the exome sequencing of a patient with cerebellar ataxia. Genetic investigations identified rare variants in the SPG11 gene in association with the clinical phenotype, which gene was originally described in the background of hereditary spastic paraparesis. Our article highlights that in certain cases the variability of the leading presenting symptom makes it hard to select the correct gene panel. In our case the variants in the gene, formerly associated to hereditary spastic paraparesis, resulted in cerebellar ataxia initially, so even an ataxia NGS gene panel would not detect those. Orv Hetil. 2018; 159(28): 1163–1169.

OBJECTIVE: Next-generation sequencing is increasingly utilized worldwide as a research and diagnostic tool and is anticipated to be implemented into everyday clinical practice. Since Central-Eastern European attitude toward genetic testing, especially broad genetic testing, is not well known, we performed a survey on this issue among Hungarian participants. METHODS: A self-administered questionnaire was distributed among patients and patient relatives at our neurogenetic outpatient clinic. Members of the general population were also recruited via public media. We used chi-square testing and binary logistic regression to examine factors influencing attitude. RESULTS: We identified a mixed attitude toward genetic testing. Access to physician consultation positively influenced attitude. A higher self-determined genetic familiarity score associated with higher perceived genetic influence score, which in turn associated with greater willingness to participate in genetic testing. Medical professionals constituted a skeptical group. CONCLUSIONS: We think that given the controversies and complexities of the next-generation sequencing field, the optimal clinical translation of NGS data should be performed in institutions which have the unique capability to provide interprofessional health education, transformative biomedical research, and crucial patient care. With optimization of the clinical translational process, improvement of genetic literacy may increase patient engagement and empowerment. RELEVANCE OF THE ARTICLE FOR PREDICTIVE, PREVENTIVE, AND PERSONALIZED MEDICINE: The paper highlights that in countries with relatively low-genetic literacy, a special strategy is needed to enhance the implementation of personalized medicine.

Background The etiology of autism spectrum disorders (ASD) is very heterogeneous. Mitochondrial dysfunction has been described in ASD; however, primary mitochondrial disease has been genetically proven in a small subset of patients. The main goal of the present study was to investigate correlations between mitochondrial DNA (mtDNA) changes and alterations of genes associated with mtDNA maintenance or ASD. Methods Sixty patients with ASD and sixty healthy individuals were screened for common mtDNA mutations. Next generation sequencing was performed on patients with major mtDNA deletions (mtdel-ASD) using two gene panels to investigate nuclear genes that are associated with ASD or are responsible for mtDNA maintenance. Cohorts of healthy controls, ASD patients without mtDNA alterations, and patients with mitochondrial disorders (non-ASD) harbouring mtDNA deletions served as comparison groups. Results MtDNA deletions were confirmed in 16.6% (10/60) of patients with ASD (mtdel-ASD). In 90% of this mtdel-ASD children we found rare SNVs in ASD-associated genes (one of those was pathogenic). In the intergenomic panel of this cohort one likely pathogenic variant was present. In patients with mitochondrial disease in genes responsible for mtDNA maintenance pathogenic mutations and variants of uncertain significance (VUS) were detected more frequently than those found in patients from the mtdel-ASD or other comparison groups. In healthy controls and in patients without a mtDNA deletion, only VUS were detected in both panel. Conclusions MtDNA alterations are more common in patients with ASD than in control individuals. MtDNA deletions are not isolated genetic alterations found in ASD; they coexist either with other ASD-associated genetic risk factors or with alterations in genes responsible for intergenomic communication. These findings indicate that mitochondrial dysfunction is not rare in ASD. The occurring mtDNA deletions in ASD may be mostly a consequence of the alterations of the causative culprit genes for autism or genes responsible for mtDNA maintenance, or because of the harmful effect of environmental factors. Electronic supplementary material The online version of this article (10.1186/s12993-018-0135-x) contains supplementary material, which is available to authorized users.

Our study analyzed lymphocyte subpopulations of 32 monozygotic twins and compared the level of the catalytic reverse transcriptase protein subunit (hTERT) in T lymphocytes (Tly), helper- (Th), cytotoxic- (Tc) and regulatory T cell (Treg) subgroups. Four variables related to telomere and mitochondrial biology were simultaneously assessed, applying multi-parametric flow cytometry, TRAP-ELISA assay and qPCR standard curve method on peripheral blood mononuclear cell (PBMC) samples of genetically matched individuals. Twin data of telomerase activity (TA), hTERT protein level, telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) were analyzed for co-twin similarity. The present study has provided novel information by demonstrating very high intraclass correlation (ICC) of hTERT protein level in T lymphocytes (0.891) and in both Th (0.896), Treg (0.885) and Tc (0.798) cell subgroups. When comparing results measured from PBMCs, intraclass correlation was also high for telomere length (0.815) and considerable for mtDNA copy number (0.524), and again exceptionally high for the rate-limiting telomerase subunit, hTERT protein level (0.946). In contrast, telomerase activity showed no co-twin similarity (ICC 0). By comparing relative amounts of hTERT protein levels in different lymphocyte subgroups of twin subjects, in Treg cells significantly higher level could be detected compared to Tly, Th or Tc cell subgroups. This is the first study that simultaneously analyzed co-twin similarity in MZ twins for the above four variables and alongside assessed their relationship, whereby positive association was found between TL and mtDNAcn.

The genetic analysis of early-onset Parkinsonian disorder (EOPD) is part of the clinical diagnostics. Several genes have been implicated in the genetic background of Parkinsonism, which is clinically indistinguishable from idiopathic Parkinson’s disease. The identification of patient’s genotype could support clinical decision-making process and also track and analyse outcomes in a comprehensive fashion. The aim of our study was to analyse the genetic background of EOPD in a Hungarian cohort and to evaluate the clinical usefulness of different genetic investigations. The age of onset was between 25 and 50 years. To identify genetic alterations, multiplex ligation-dependent probe amplification (n = 142), Sanger sequencing of the most common PD-associated genes (n = 142), and next-generation sequencing (n = 54) of 127 genes which were previously associated to neurodegenerative disorders were carried out. The genetic analysis identified several heterozygous damaging substitutions in PD-associated genes (C19orf12, DNAJC6, DNAJC13, EIF4G1, LRRK2, PRKN, PINK1, PLA2G6, SYNJ1). CNVs in PRKN and SNCA genes were found in five patients. In our cohort, nine previously published genetic risk factors were detected in three genes (GBA, LRRK2, and PINK1). In nine cases, two or three coexisting pathogenic mutations and risk variants were identified. Advances of sequencing technologies make it possible to aid diagnostics of PD by widening the scope of analysis to genes which were previously linked to other neurodegenerative disorders. Our data suggested that rare damaging variants are enriched versus neutral variants, among PD patients in the Hungarian population, which raise the possibility of an oligogenic effect. Heterozygous mutations of multiple recessive genes involved in the same pathway may perturb the molecular process linked to PD pathogenesis. Comprehensive genetic assessment of individual patients can rarely reveal monogenic cause in EOPD, although it may identify the involvement of multiple PD-associated genes in the background of the disease and may facilitate the better understanding of clinically distinct phenocopies. Due to the genetic complexity of the disease, genetic counselling and management is getting more challenging. Clinical geneticist should be prepared for counselling of patients with coexisting disease-causing mutations and susceptibility factors. At the same time, genomic-based stratification has increasing importance in future clinical trials.

Background Parkinsonism is a complex multifactorial neurodegenerative disorder, in which genetic and environmental risk factors may both play a role. Among environmental risk factors cocaine was earlier ambiguously linked to Parkinsonism. Former single case reports described Parkinsonism in chronic cocaine users, but an epidemiological study did not confirm an increased risk of Parkinson’s disease. Here we report a patient, who developed Parkinsonism in young age after chronic cocaine use, in whom a homozygous LRRK2 risk variant was also detected. Case presentation The patient was investigated because of hand tremor, which started after a 1.5-year period of cocaine abuse. Neurological examination suggested Parkinsonism, and asymmetrical pathology was confirmed by the dopamine transporter imaging study. The genetic investigations revealed a homozygous risk allele in the LRRK2 gene. After a period of cocaine abstinence, the patient’s symptoms spontaneously regressed, and the dopamine transporter imaging also returned to near-normal. Conclusions This case report suggests that cocaine abuse indeed might be linked to secondary Parkinsonism and serves as an example of a potential gene-environmental interaction between the detected LRRK2 risk variant and cocaine abuse. The reversible nature of the DaTscan pathology is a unique feature of this case, and needs further evaluation, whether this is incidental or can be a feature of cocaine related Parkinsonism.

Background Autism spectrum disorder (ASD) is genetically and phenotypically heterogeneous. Former genetic studies suggested that both common and rare genetic variants play a role in the etiology. In this study, we aimed to analyze rare variants detected by next generation sequencing (NGS) in an autism cohort from Hungary. Methods We investigated the yield of NGS panel sequencing of an unselected ASD cohort (N = 174 ) for the detection of ASD associated syndromes. Besides, we analyzed rare variants in a common disease-rare variant framework and performed rare variant burden analysis and gene enrichment analysis in phenotype based clusters. Results We have diagnosed 13 molecularly proven syndromic autism cases. Strongest indicators of syndromic autism were intellectual disability, epilepsy or other neurological plus symptoms. Rare variant analysis on a cohort level confirmed the association of five genes with autism (AUTS2, NHS, NSD1, SLC9A9, and VPS13). We found no correlation between rare variant burden and number of minor malformation or autism severity. We identified four phenotypic clusters, but no specific gene was enriched in a given cluster. Conclusion Our study indicates that NGS panel gene sequencing can be useful, where the clinical picture suggests a clinically defined syndromic autism. In this group, targeted panel sequencing may provide reasonable diagnostic yield. Unselected NGS panel screening in the clinic remains controversial, because of uncertain utility, and difficulties of the variant interpretation. However, the detected rare variants may still significantly influence autism risk and subphenotypes in a polygenic model, but to detect the effects of these variants larger cohorts are needed.

We describe a family with a novel TNPO3 mutation of limb–girdle muscular dystrophy D2 (or LGMD 1F), a rare muscle disorder with autosomal dominant inheritance, first identified in an Italo-Spanish family where the causative defect has been found to be due to TNPO3 gene mutation, encoding transportin-3 protein (TNPO3). We present the clinical, histopathological and muscle magnetic resonance imaging (MRI) features in two patients, mother and son Hungarian origin, affected by LGMD D2 and correlate their clinical, MRI and histopathological data found in this condition. The affected son presented early pelvic girdle muscle weakness and thin muscles similar to a congenital myopathy; the mother was less compromised and had an LGMD phenotype. Muscle MRI showed a very pronounced lower limb muscle atrophy in both patients. The most relevant change obtained in the child muscle biopsy was a generalized type 1 fibre atrophy. The two patients presented the same mutation, but a different phenotype has been observed in mother and son.

ObjectiveOur aim was to study a Hungarian family with autosomal dominantly inherited neurodegeneration with brain iron accumulation (NBIA) with markedly different intrafamilial expressivity.MethodsTargeted sequencing and multiplex ligation-dependent probe amplification (MLPA) of known NBIA-associated genes were performed in many affected and unaffected members of the family. In addition, a trio whole-genome sequencing was performed to find a potential explanation of phenotypic variability. Neuropathologic analysis was performed in a single affected family member.ResultsThe clinical phenotype was characterized by 3 different syndromes—1 with rapidly progressive dystonia-parkinsonism with cognitive deterioration, 1 with mild parkinsonism associated with dementia, and 1 with predominantly psychiatric symptoms along with movement disorder. A heterozygous stop-gain variation in theC19Orf12gene segregated with the phenotype. Targeted sequencing of all known NBIA genes, and MLPA ofPLA2G6andPANK2genes, as well as whole-genome sequencing in a trio from the family, revealed a unique constellation of oligogenic burden in 3 NBIA-associated genes (C19Orf12p.Trp112Ter,CPp.Val105PhefsTer5, andPLA2G6dup(ex14)). Neuropathologic analysis of a single case (39-year-old man) showed a complex pattern of alpha-synucleinopathy and tauopathy, both involving subcortical and cortical areas and the hippocampus.ConclusionsOur study expands the number of cases reported with autosomal dominant mitochondrial membrane protein-associated neurodegeneration and emphasizes the complexity of the genetic architecture, which might contribute to intrafamilial phenotypic variability.

Introduction: Wernicke encephalopathy (WE) and Wernicke–Korsakoff syndrome (WKS) are well-known disorders caused by thiamine deficiency. In addition to the classical concept of these diseases, some literature data suggest a connection between mitochondrial dysfunction and WE/WKS. Psychotic disorders and WKS seem to run in families, as the deficiency of the oxidative phosphorylation can be a trigger factor in psychotic events and WE/WKS as well. We present a patient harbouring the m.A3243G mtDNA mutation with the clinical and magnetic resonance imaging (MRI) findings of WKS who developed schizophrenia with predominantly negative symptoms some years later. Case presentation: A 27-year-old woman was referred to our clinic with severe weight loss after severe vomiting episodes, memory dysfunction and gait ataxia. Family history, as well as clinical, imaging and laboratory findings suggested a mitochondrial aetiology of her symptoms. Brain MRI detected bilateral mild thalamic lesions and loss of corpus mammillae, indicating Wernicke encephalopathy. Genetic testing detected an m.A3243G mtDNA mutation, which has been frequently associated with mitochondrial encephalopathy with lactic acidosis and stroke-like episodes. High-dose vitamin B1 supplementation with supportive antioxidant therapy improved the patient’s memory and learning disturbance; however, some months later she developed psychosis with predominantly negative symptoms and her cognitive functions deteriorated again. Both cognitive and negative symptoms responded well to cariprazine monotherapy. Discussion: Mitochondrial disease due to mtDNA alteration can be a rare cause of WE. In addition to vitamin B1 supplementation, cariprazine with significant dopamine D3 receptor binding can be useful to treat the predominantly negative symptoms and cognitive dysfunction in patients with mitochondrial dysfunction. Conclusion: We assume that patients with a mitochondrial disorder might be prone to develop WE/WKS and therefore need tailored supportive therapy during metabolic crisis as well as symptom-based personalized antipsychotic treatment.

Background: NKX2-1 related disorders (also known as brain-lung-thyroid syndrome or benign hereditary chorea 1) are associated with a wide spectrum of symptoms. The core features are various movement disorders, characteristically chorea, less frequently myoclonus, dystonia, ataxia; thyroid disease; and lung involvement. The full triad is present in 50% of affected individuals. Numerous additional symptoms may be associated, although many of these were reported only in single cases. Pituitary dysfunction was ambiguously linked to NKX2-1 haploinsufficiency previously. Case Presentation: We examined two members of a family with motor developmental delay, mixed movement disorder (myoclonus, dystonia and chorea) and endocrinological abnormalities (peripheric thyroid disease, and pituitary hormone deficiencies). Dystonia predominated at the father, and myoclonus at the daughter. The father had hypogonadotropic hypogonadism, while the daughter was treated with growth hormone deficiency. Both patients had empty sella on MRI. Candidate gene analyses were negative. Exome sequencing detected a pathogenic stop variation ({"type":"entrez-nucleotide","attrs":{"text":"NM_003317","term_id":"1677498761","term_text":"NM_003317"}}NM_003317:c.338G>A, p.Trp113*) in the NKX2-1 gene. Conclusions: This case study has two highlights. (1) It draws attention to possible pituitary dysfunction in brain-lung-thyroid syndrome, and provide further evidences that this might be linked to loss of function of the NKX2-1 gene. (2) It underscores the importance of considering NKX2-1 related disorders in the differential diagnosis of myoclonus dystonia.

Background Premature ovarian failure / primary ovarian insufficiency (POF/POI) associated with the mutations of the FMR1 (Fragile-X Mental Retardation 1) gene belongs to the group of the so-called trinucleotide expansion diseases. Our aim was to analyse the relationship between the paternally inherited premutation (PIP) and the maternally inherited premutation (MIP) by the examination of the family members of women with POF, carrying the premutation allele confirmed by molecular genetic testing. Methods Molecular genetic testing was performed in the patients of the 1st Department of Obstetrics and Gynecology with suspected premature ovarian failure. First we performed the southern blot analyses and for the certified premutation cases we used the Repeat Primed PCR. Results Due to POF/POI, a total of 125 patients underwent genetic testing. The FMR1 gene trinucleotide repeat number was examined in the DNA samples of the patients, and in 15 cases (12%) deviations (CGG repeat number corresponding to premutation or gray zone) were detected. In 6 cases out of the 15 cases the CGG repeat number fell within the range of the so-called gray zone (41–54 CGG repeat) (4.8%, 6/125), and the FMR1 premutation (55–200 CGG repeat) ratio was 7.2% (9/125). In 4 out of the 15 cases we found differences in both alleles, one was a premutation allele, and the other allele showed a repeat number belonging to the gray zone. Out of 15 cases, only maternal inheritance (MIP) was detected in 2 cases, in one case the premutation allele (91 CGG repeat number), while in the other case an allele belonging to the gray zone (41 CGG repeat number) were inherited from their mothers. In 10 out of 15 cases, the patient inherited the premutation allele only from the father (PIP). In 5 out of the 10 cases (50%) the premutation allele was inherited from the father, and the repeat number ranged from 55 to 133. Out of 125 cases, 9 patients had detectable cytogenetic abnormalities (7.2%). Conclusions The RP-PCR method can be used to define the smaller premutations and the exact CGG number. Due to the quantitative nature of the RP-PCR, it is possible to detect the mosaicism as well.

Introduction Recent experimental and population studies have highlighted the existence of telomere-mitochondria interplay. Besides studies revealing the molecular mechanisms underlying the associations of telomere defects and mitochondrial functions, investigations of mitochondrial DNA copy number (mtDNAcn) and telomere length (TL) in healthy and disease phenotypes have likewise begun, with the aim of gaining more insights about their relationship in humans. Material and methods A total of 142 asymptomatic adult twins, comprising 96 monozygotic (MZ) and 46 dizygotic (DZ) twins (mean age: 50.54 ±15.43 years), members of the Hungarian Twin Registry, were included in the analysis. Applying the qPCR standard curve method, we investigated the relationship of mtDNA copy number, telomere length and clinical data, besides assessing co-twin similarities of MZ and DZ twins for their mtDNAcn and TL measures. Results We found that twins were similar in their intraclass correlation coefficients irrespective of zygosity, suggesting a possibly more important role of common (shared) environmental factors compared to non-shared (unique) environmental and to a smaller degree also individual genetic influences. We confirmed a significant positive association between mtDNAcn and TL (r = 0.28, p < 0.01) in age- and sex-corrected analysis. Following bivariate estimates and correction with significant predictors, the independent positive associations were further verified. Conclusions Our results extend the until now modest number of studies investigating mtDNAcn and TL simultaneously in humans. In addition, we are the first to examine the relationship between mtDNAcn and telomere length in MZ and DZ twin subjects.

Pathogenic variants of the gap junction beta 2 (GJB2) gene are responsible for about 50% of hereditary non-syndromic sensorineural hearing loss (NSHL). In this study, we report mutation frequency and phenotype comparison of different GJB2 gene alterations in Hungarian NSHL patients. The total coding region of the GJB2 gene was analyzed with Sanger or NGS sequencing for 239 patients with NSHL and 160 controls. Homozygous and compound heterozygous GJB2 mutations were associated with early onset serious clinical phenotype in 28 patients. In 24 patients, two deletion or nonsense mutations were detected in individuals with mainly prelingual NSHL. In compound heterozygous cases, a combination of deletion and missense mutations associated with milder postlingual NSHL. A further 25 cases harbored single heterozygous GJB2 mutations mainly associated with later onset, milder clinical phenotype. The most common mutation was the c.35delG deletion, with 12.6% allele frequency. The hearing loss was more severe in the prelingual groups. The mutation frequency of GJB2 in the investigated cohort is lower than in other European cohorts. The most serious cases were associated with homozygous and compound heterozygous mutations. In our cohort the hearing impairment and age of onset was not altered between in cases with only one heterozygous GJB2 mutation and wild type genotype, which may exclude the possibility of autosomal dominant inheritance. In early onset, severe to profound hearing loss cases, if the GJB2 analysis results in only one heterozygous alteration further next generation sequencing is highly recommended.

Mitochondrial disorders represent a major challenge in medicine. Most of the mitochondrial proteins are encoded by the nuclear DNA (nDNA), whereas a very small fraction is encoded by the mitochondrial DNA (mtDNA). Mutations in mtDNA or mitochondria-related nDNA genes can result in mitochondrial dysfunction. The disease usually affects multiple organs in varying locations and severity; however, there are some forms which affect a single organ. The diagnosis of mitochondrial disorders is based on clinical examination, biochemical and histopathologic examinations, functional studies, and molecular genetic testing. Neuropathologic alterations of the muscle are variable and can range from striking abnormalities, such as cytochrome oxidase-negative and ragged red fibers, to nonspecific or minimal changes. Neuropathologic alterations in the brain show common features in disorders with different genetic background. These are characterized by various degrees of vacuolation in the white and gray matter, regional neurodegeneration with reactive astrogliosis, loss of oligodendrocytes, presence of macrophages and microgliosis, capillary proliferation, and mineralization of vessel walls. The advent of molecular genetics, the discovery of biomarkers and new sequencing platforms to perform targeted exome and whole-genome sequencing have changed traditional approaches to diagnose mitochondrial diseases.

Many individuals with Parkinson's disease (PD) develop cognitive deficits, and a phenotypic and molecular overlap between neurodegenerative diseases exists. We investigated the contribution of rare variants in seven genes of known relevance to dementias (β-amyloid precursor protein (APP), PSEN1/2, MAPT (microtubule-associated protein tau), fused in sarcoma (FUS), granulin (GRN) and TAR DNA-binding protein 43 (TDP-43)) to PD and PD plus dementia (PD+D) in a discovery sample of 376 individuals with PD and followed by the genotyping of 25 out of the 27 identified variants with a minor allele frequency5% in 975 individuals with PD, 93 cases with Lewy body disease on neuropathological examination, 613 individuals with Alzheimer's disease (AD), 182 cases with frontotemporal dementia and 1014 general population controls. Variants identified in APP were functionally followed up by Aβ mass spectrometry in transiently transfected HEK293 cells. PD+D cases harbored more rare variants across all the seven genes than PD individuals without dementia, and rare variants in APP were more common in PD cases overall than in either the AD cases or controls. When additional controls from publically available databases were added, one rare variant in APP (c.1795GA(p.(E599K))) was significantly associated with the PD phenotype but was not found in either the PD cases or controls of an independent replication sample. One of the identified rare variants (c.2125GA (p.(G709S))) shifted the Aβ spectrum from Aβ40 to Aβ39 and Aβ37. Although the precise mechanism remains to be elucidated, our data suggest a possible role for APP in modifying the PD phenotype as well as a general contribution of genetic factors to the development of dementia in individuals with PD.

The most frequent form of hereditary blindness, autosomal dominant optic atrophy (ADOA), is caused by the mutation of the mitochondrial protein Opa1 and the ensuing degeneration of retinal ganglion cells. Previously we found that knockdown of OPA1 enhanced mitochondrial Ca2+ uptake (Fulop et al., 2011). Therefore we studied mitochondrial Ca2+ metabolism in fibroblasts obtained from members of an ADOA family. Gene sequencing revealed heterozygosity for a splice site mutation (c. 984+1G>A) in intron 9 of the OPA1 gene. ADOA cells showed a higher rate of apoptosis than control cells and their mitochondria displayed increased fragmentation when forced to oxidative metabolism. The ophthalmological parameters critical fusion frequency and ganglion cell–inner plexiform layer thickness were inversely correlated to the evoked mitochondrial Ca2+ signals. The present data indicate that enhanced mitochondrial Ca2+ uptake is a pathogenetic factor in the progress of ADOA.

Charcot-Marie-Tooth neuropathy (CMT) is a genetically and clinically heterogeneous group of neuromuscular disorders with an overall prevalence of 1 per 2500. Here we report the first comprehensive genetic epidemiology study of Hungarian CMT patients. 409 CMT1 and 122 CMT2 patients were enrolled and genetic testing of PMP22, GJB1, MPZ, EGR2 and MFN2 genes were performed routinely. NDRG1 and CTDP1 genes were screened only for founder mutations in Roma patients. Causative genetic mutations were identified in 67.2% of the CMT1 and in 33.6% of the CMT2 cases, which indicates an overall success rate of 59.9% in the study population. Considering all affected individuals, alterations were most frequently found in PMP22 (40.5%), followed by GJB1 (9.2%), MPZ (4.5%), MFN2 (2.5%), NDRG1 (1.5%), EGR2 (0.8%) and CTDP1 (0.8%). The phenotypic spectrum and the disease severity of the studied patients also varied broadly. Deafness and autoimmune disorders were more often associated with PMP22 duplication, while MFN2 and GJB1 mutations were frequently present with central nervous system abnormalities. Our study may be helpful in determining the strategy of genetic diagnostics in Hungarian CMT patients.

The protein MSTO1 has been localized to mitochondria and linked to mitochondrial morphology, but its specific role has remained unclear. We identified a c.22G > A (p.Val8Met) mutation of MSTO1 in patients with minor physical abnormalities, myopathy, ataxia, and neurodevelopmental impairments. Lactate stress test and myopathological results suggest mitochondrial dysfunction. In patient fibroblasts, MSTO1 mRNA and protein abundance are decreased, mitochondria display fragmentation, aggregation, and decreased network continuity and fusion activity. These characteristics can be reversed by genetic rescue. Short‐term silencing of MSTO1 in HeLa cells reproduced the impairment of mitochondrial morphology and dynamics observed in the fibroblasts without damaging bioenergetics. At variance with a previous report, we find MSTO1 to be localized in the cytoplasmic area with limited colocalization with mitochondria. MSTO1 interacts with the fusion machinery as a soluble factor at the cytoplasm‐mitochondrial outer membrane interface. After plasma membrane permeabilization, MSTO1 is released from the cells. Thus, an MSTO1 loss‐of‐function mutation is associated with a human disorder showing mitochondrial involvement. MSTO1 likely has a physiologically relevant role in mitochondrial morphogenesis by supporting mitochondrial fusion.

We have recently shown that the ATP-forming SUCLA2 subunit of succinyl-CoA ligase, an enzyme of the citric acid cycle, is exclusively expressed in neurons of the human cerebral cortex; GFAP- and S100-positive astroglial cells did not exhibit immunohistoreactivity or in situ hybridization reactivity for either SUCLA2 or the GTP-forming SUCLG2. However, Western blotting of post mortem samples revealed a minor SUCLG2 immunoreactivity. In the present work we sought to identify the cell type(s) harboring SUCLG2 in paraformaldehyde-fixed, free-floating surgical human cortical tissue samples. Specificity of SUCLG2 antiserum was supported by co-localization with mitotracker orange staining of paraformaldehyde-fixed human fibroblast cultures, delineating the mitochondrial network. In human cortical tissue samples, microglia and oligodendroglia were identified by antibodies directed against Iba1 and myelin basic protein, respectively. Double immunofluorescence for SUCLG2 and Iba1 or myelin basic protein exhibited no co-staining; instead, SUCLG2 appeared to outline the cerebral microvasculature. In accordance to our previous work there was no co-localization of SUCLA2 immunoreactivity with either Iba1 or myelin basic protein. We conclude that SUCLG2 exist only in cells forming the vasculature or its contents in the human brain. The absence of SUCLA2 and SUCLG2 in human glia is in compliance with the presence of alternative pathways occurring in these cells, namely the GABA shunt and ketone body metabolism which do not require succinyl CoA ligase activity, and glutamate dehydrogenase 1, an enzyme exhibiting exquisite sensitivity to inhibition by GTP.

Focusing on the benefits of patients with rare disease the authors analysed the aspects of orphan medicines financed in the frame of the Hungarian social insurance system in 2012 in order to make the consumption more rational, transparent and predictable. Most of the orphan drugs were financed in the frame of compassionate use by the reimbursement system. Consequently, a great deal of crucial problems occurred in relation to the unconventional subsidized method, especially in the case of the highest cost enzyme replacement therapies. On the base of the findings, proposals of the authors are presented for access to orphan drugs, fitting to the specific professional, economical and ethical aspects of this unique field of the health care system. The primary goal is to provide a suitable subsidized method for the treatment of rare disease patients with unmet medical needs. The financial modification of orphans became indispensible in Hungary. Professionals from numerous fields dealing with rare disease patients’ care expressed agreement on the issue. Transforming the orphan medicines’ financial structure has been initiated according to internationally shared principles. Orv. Hetil., 2014, 155(44), 1735–1741.

A 9-bp deletion of the mtDNA is known as an anthropological marker of people with East-Asian origin. This 9-bp mtDNA deletion was analyzed in 1073 Hungarians with suspected mitochondrial disease and in 468 healthy control individuals. Fourteen cases with the 9-bp deletion were found in the cohort of mitochondrial patients, and one individual from 468 controls. In six cases the 9-bp deletion was present together with pathogenic major deletions in the mitochondrial genome. In one patient we found a frame shift mutation in the D-loop region, and in another family a pathogenic m.8322 A > G mutation in the tRNALys gene. Although the 9-bp deletion is common in the populations of the Pacific region and Asia, it is present in the Hungarian population as well. This 9-bp deletion may induce instability of the mtDNA and may provoke the introduction of other pathogenic mutations.

Cerebrotendinous xanthomatosis is a rare neurodegenerative disease characterized by the accumulation of cholesterol and cholestanol in the brain and the tendons caused by mutations of the gene encoding sterol 27-hydroxylase (CYP27A1), which is involved in bile acid synthesis. The diagnosis is often missed and delayed because of the variable clinical presentation of the disease. Blood testing for cerebrotendinous xanthomatosis is routinely performed using gas chromatography-mass spectrometry measurement of elevated cholestanol level, and the diagnosis is confirmed by molecular genetic analysis. Early recognition and initiation of chenodeoxycholic acid therapy with hydoxymethyl‑glutaryl‑Coenzyme-A reductase inhibitors is critical to prevent irreversible neurological damage and permanent disability. The authors summarize the current knowledge about the pathomechanism, laboratory diagnosis and therapeutic options of cerebrotendinous xanthomatosis.A cerebrotendinosus xanthomatosis egy ritka, ataxiával, spasticitassal, korai mentális hanyatlással és pszichiátriai tünetekkel járó neurodegeneratív betegség, amelyet a koleszterin és a kolesztanol agyban és az inakban történő felszaporodása jellemez az epesavszintézisben részt vevő szterol-27-hidroxiláz (CYP27A1) génjének mutációja miatt. A diagnózis gyakran hibás vagy megkésett a változatos klinikai megjelenés miatt. A laboratóriumi diagnosztika rutinszerűen az emelkedett kolesztanolszint kimutatását végzi gázkromatográf-tömegspektrométer alkalmazásával, majd a diagnózist a molekuláris genetikai vizsgálat igazolja. A korai felismerés és a kenodezoxikólsav-, valamint a hidroximetil-glutaril-koenzim-A-reduktáz-gátló kezelés megkezdése alapvető jelentőségű az irreverzíbilis neurológiai károsodások és a tartós munkaképtelenség kialakulásának megelőzésében. A szerzők összefoglalják a cerebrotendinosus xanthomatosis patomechanizmusával, laboratóriumi diagnosztikájával és kezelési lehetőségeivel kapcsolatos tudnivalókat. Orv. Hetil., 2014, 155(21), 811–816.

SUCLA2 encodes the ATP-forming β subunit (A-SUCL-β) of succinyl-CoA ligase, an enzyme of the citric acid cycle. Mutations in SUCLA2 lead to a mitochondrial disorder manifesting as encephalomyopathy with dystonia, deafness and lesions in the basal ganglia. Despite the distinct brain pathology associated with SUCLA2 mutations, the precise localization of SUCLA2 protein has never been investigated. Here, we show that immunoreactivity of A-SUCL-β in surgical human cortical tissue samples was present exclusively in neurons, identified by their morphology and visualized by double labeling with a fluorescent Nissl dye. A-SUCL-β immunoreactivity co-localized >99 % with that of the d subunit of the mitochondrial F0–F1 ATP synthase. Specificity of the anti-A-SUCL-β antiserum was verified by the absence of labeling in fibroblasts from a patient with a complete deletion of SUCLA2. A-SUCL-β immunoreactivity was absent in glial cells, identified by antibodies directed against the glial markers GFAP and S100. Furthermore, in situ hybridization histochemistry demonstrated that SUCLA2 mRNA was present in Nissl-labeled neurons but not glial cells labeled with S100. Immunoreactivity of the GTP-forming β subunit (G-SUCL-β) encoded by SUCLG2, or in situ hybridization histochemistry for SUCLG2 mRNA could not be demonstrated in either neurons or astrocytes. Western blotting of post mortem brain samples revealed minor G-SUCL-β immunoreactivity that was, however, not upregulated in samples obtained from diabetic versus non-diabetic patients, as has been described for murine brain. Our work establishes that SUCLA2 is expressed exclusively in neurons in the human cerebral cortex.

The rare, genetically determined group of diseases characterized by pathological accumulation of iron in the central nervous system and progressive, typically movement disorder's symptoms are called NBIA (neurodegeneration with brain iron accumulation). By the rapid development of molecular genetics, it has become apparent that different mutations in numerous genes can lead to pathological cerebral iron accumulation. Simultaneously, it has also been recognized that the age of onset, the symptoms and the prognosis of NBIA disorders are much more diverse than it was previously perceived. To our knowledge, a review article on the most recent clinical data of NBIA has not been published in Hungarian. In the first part of this publication, we survey the general clinical characteristics and the diagnostic algorithm of NBIA diseases and address some considerations for differential diagnostics. In the second part of this review, the particular NBIA disorders are presented in details. The purpose of this article is to provide a clinical overview that may be useful for neurologists, pediatricians and any other medical practitioners interested in this field.

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with unknown genetic and environmental causation in most of the affected individuals. On the other hand, there are a growing number of ASD-associated syndromes, where the exact genetic origin can be revealed. Here we report a method, which included the targeted next generation sequencing (NGS) and filtering of 101 ASD associated genes, followed by database search. Next, RNA sequencing was used to study the region of interest at the transcriptional level. Using this workflow, we identified a de novo mutation in the euchromatic histone-lysine N-methyltransferase 1 gene (EHMT1) of an autistic patient with dysmorphisms. Sequencing of EHMT1 transcripts showed that the premature termination codon (Trp1138Ter) created by a single nucleotide change elicited nonsense-mediated mRNA decay, which led to haploinsufficiency already at the transcriptional level. Database and literature search provided evidence that this mutation caused Kleefstra syndrome (KS), which was confirmed by the presence of the disorder-specific phenotype in the patient. We provide a proof of principle that the implemented method is capable to elucidate the genetic etiology of individuals with syndromic autism. The novel mutation detected in the EHMT1 gene is responsible for KS's symptoms. In addition, further genetic factors might be involved in the ASD pathogenesis of the patient including a missense DPP6 mutation (Arg322Cys), which segregated with the autistic phenotype within the family.

There are several neuro-ophthalmological disorders that have genetic abnormalities in the background. Part of these diseases has monogenic, that is, autosomal dominant, recessive or maternal inheritance, while others pertain to the polygenic and multifactorial disease categories. This section summarizes the most frequent monogenic neuro-ophtalmological diseases in clinical practice.

From the electrophysiological examinations, electromyography (EMG) and electroneurography (ENG) help neurologists and neuro-ophthalmologists in diagnosing diseases affecting the skeletal muscle, the neuromuscular junction, or the peripheral nerves, or if the neuro-ophthalmological symptom is part of a multisystemic disease affecting one of the above organs. This chapter briefly describes the role of EMG–ENG examinations in neuro-ophtalmologic diseases and then describes the most characteristic differences that help the clinician in recognizing neuro-ophthalmological diseases.

BACKGROUND AND PURPOSE Data on the disease burden of Duchenne Muscular Dystrophy are scarce in Hungary. The aim of this study was to assess patients' and their caregivers' health related quality of life and healthcare utilisations. METHODS A cross sectional survey was performed as part of the European BURQOL-RD project. The EQ-5D-5L and Barthel Index questionnaires were applied, health care utilisations and patients' informal carers were surveyed. RESULTS One symptomatic female carer, 50 children (boys 94%) and six adult patients (five males) participated in the study, the latter two subgroups were included in the analysis. The average age was 9.7 (SD = 4.6) and 24.3 (SD = 9.8) years, respectively. Median age at time of diagnosis was three years. The average EQ-5D score among children and adults was 0.198 (SD = 0.417) and 0.244 (SD = 0.322), respectively, the Barthel Index was 57.6 (SD = 29.9) and 53.0 (SD = 36.5). Score of satisfaction with healthcare (10-point Likert-scale) was mean 5.3 (SD = 2.1) and 5.3 (SD = 2.9). 15 children were hospitalised in the past 12 months for mean 12.9 (SD = 24.5) days. Two patients received help from professional carer. 25 children (mean age 11.1, SD = 4.4 years) were helped/supervisied by principal informal carer (parent) for mean 90.1 (SD = 44.4) hours/week and further family members helped in 21 cases. Correlation between EQ-5D and Barthel Index was strong and significant (0.731; p < 0.01) as well as with informal care time (-0.770; p < 0.01), but correlation with satisfaction with health care was not significant (EQ-5D: 0.241; Barthel Index: 0.219; informal care: -0.142). CONCLUSION Duchenne muscular dystrophy leads to a significant deterioration in the quality of life of patients. Parents play outstanding role in the care of affected children. This study is the first in the Central and Eastern European region that provides quality of life data in this rare disease for further health economic studies.