About
94
Publications
9,348
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
729
Citations
Introduction
Additional affiliations
April 2014 - May 2015
January 2008 - March 2016
Publications
Publications (94)
We present a male patient carrying a pathogenic MECP2 p. Arg179Trp variant with predominant negative psychiatric features and multilevel evidence of mitochondrial dysfunction who responded to the cariprazine treatment. He had delayed speech development and later experienced severe social anxiety, learning disabilities, cognitive slowing, and predom...
Introduction
Early-onset dementias (EOD) are predominantly genetically determined, but the underlying disease-causing alterations are often unknown. The most frequent forms of EODs are early-onset Alzheimer’s disease (EOAD) and frontotemporal dementia (FTD).
Patients
This study included 120 Hungarian patients with EOD (48 familial and 72 sporadic)...
Bevezetés: A MELAS-szindróma (mitokondriális myopathia, encephalopathia, tejsavas acidózis és stroke) a leggyakrabban előforduló mitokondriális betegség. Tünetei a mitokondriális betegségekre jellemzően igen heterogének, és nem ritka a szemészeti érintettség. Esetismertetés: Három MELAS-szindrómás nőbeteg – egy édesanya és két leánya – esetét ismer...
Introduction
Phospholipase 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.
Meth...
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...
Objective
Our aim was to study a Hungarian family with autosomal dominantly inherited neurodegeneration with brain iron accumulation (NBIA) with markedly different intrafamilial expressivity.
Methods
Targeted sequencing and multiplex ligation-dependent probe amplification (MLPA) of known NBIA-associated genes were performed in many affected and un...
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 deficien...
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 myo...
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 t...
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 als...
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 t...
Number of variants in the investigated genes. Table summarizes the number of different variant types, detected in the investigated genes. Table only includes rare variants, as defined in the Section “Materials and Methods.” n/a, not applicable. Next generation sequencing is not suitable for detection of repeat expansion events. Repeat expansions we...
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 s...
PurposePathogenic 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. Methods
The total coding region of the GJB2 gene was analyz...
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 sequenci...
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 par...
We report here the first families carrying recessive variants in the MSTO1 gene: compound heterozygous mutations were identified in two sisters and in an unrelated singleton case, who presented a multisystem complex phenotype mainly characterized by myopathy and cerebellar ataxia. Human MSTO1 is a poorly studied protein, suggested to have mitochond...
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...
ONLINE SUPPORTING INFORMATION Recessive mutations in MSTO1 cause mitochondrial dynamics impairment, leading to myopathy and ataxia
Source Data for Figure 6
Source Data for Figure 7
Source Data for Figure 1
Source Data for Figure 4
Source Data for Figure 8
Expanded View Figures PDF
Source Data for Figure 5
Review Process File
Source Data for Figure 3
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...
We report here the first families carrying recessive variants in the MSTO1 gene: compound heterozygous mutations were identified in two sisters and in an unrelated singleton case, who presented a multisystem complex phenotype mainly characterized by myopathy and cerebellar ataxia. Human MSTO1 is a poorly studied protein, suggested to have mitochond...
Mitochondrial diseases belong to a heterogeneous group of multisystem diseases as rare systemic disorders caused by mutations of the mitochondrial genome (mtDNA) and cc. 1500 nuclear genes which are responsible for the mitochondrial function. The disease primarily affects organs with high energy expenditure as the central nervous system and skeleta...
The relevance of PiC, encoded by SLC25A3, in bioenergetics is well accepted. However, little is known about the mechanisms mediating the cellular impairments induced by pathological SLC25A3 variants. To this end, we investigated the pathogenicity of a novel compound heterozygous mutation in SLC25A3. First, each variant was modeled in yeast, reveali...
Pathogenic variants of the gap junction beta 1 (GJB1) gene are responsible for the Charcot-Marie-Tooth neuropathy X type 1 (CMTX1). In this study, we report the mutation frequency of GJB1 in 210 Hungarian CMT patients and the phenotype comparison between male and female CMTX1 patients. Altogether, 13 missense substitutions were found in the GJB1 ge...
Succinate-CoA ligase is a heterodimer enzyme composed of Suclg1 -alpha- and a substrate-specific Sucla2 or Suclg2 -beta- subunit yielding ATP or GTP, respectively. In humans, the deficiency of this enzyme leads to encephalomyopathy with, or without methylmalonyl aciduria, in addition to resulting in mitochondrial DNA depletion. We generated mice la...
The probability of mitochondrial permeability transition (mPT) pore opening is inversely related to the magnitude of the proton electrochemical gradient. The module conferring sensitivity of the pore to this gradient has not been identified. We investigated mPT’s voltage-sensing properties elicited by calcimycin or H2O2 in human fibroblasts exhibit...
Background:
Hereditary spastic paraplegias (HSPs) are a clinically and genetically heterogeneous group of neurodegenerative diseases with progressive lower limb spasticity and weakness. The aim of this study is to determine the frequency of different SPG mutations in Hungarian patients, and to provide further genotype-phenotype correlations for th...
Alterations of mitochondrial dynamics (fusion/fission and motility) and ER-mitochondria associations have emerged as feature of a number of pathways. Analysis of these aspects has remained largely qualitative and manual, limiting their potential use as biomarkers. Here we demonstrate techniques for unbiased, quantitative and automatized image analy...
Dynamin2 (DNM2) gene mutations may result in Charcot-Marie-Tooth disease and centronuclear myopathy. Here, we present a patient suffering from cardiomyopathy and centronuclear myopathy with repetitive discharges and mild axonal neuropathy due to DNM2 mutation. Detailed cardiological and neurological examinations, electrophysiological tests, muscle...
Mutations of both the PMP22 and EGR2 genes cause Charcot-Marie-Tooth (CMT) disease type 1. Deletion of the PMP22 gene, results in hereditary neuropathy with liability to pressure palsies. More publications exist about the interaction of PMP22 duplication and other CMT-causing gene mutations. In these cases the intrafamiliar discordant phenotypes dr...
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. Howev...
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 4...
Introduction: Childhood neurodegeneration with brain
iron accumulation (NBIA) presents with heterogenous
clinical manifestation. We describe a family, where
progressive neurological symptoms affected three girls
with autosomal recessive inheritance. The aim of our
investigations was to classify the genetical background of
NBIA. Genetic tests...
Mutations in the mitochondrial genome can impair normal metabolic function in the central nervous system (CNS) where cellular
energy demand is high. Primary mitochondrial DNA (mtDNA) mutations have been linked to several mitochondrial disorders that
have comorbid psychiatric, neurologic, and cognitive sequelae. Here, we present a series of cases wi...
Abstract Prevalence estimations for mitochondrial disorders still vary widely and only few epidemiologic studies have been carried out so far. With the present work we aim to give a comprehensive overview about frequencies of the most common mitochondrial mutations in Hungarian patients. A total of 1328 patients were tested between 1999 and 2012. A...
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 localizatio...
Clopidogrel is an inhibitor of platelet-aggregation used in the prevention of secondary stroke. The molecule is activated by the cytochrome P450 2C19 (CYP2C19) enzyme. The frequent CYP2C19*2 point mutation causes loss of enzyme function, a decreased (heterozygous form) or blocked (homozygous form) formation of the active molecule. Thus, for a patie...
The aim of our study was to assess psychiatric symptoms in patients with genetically proven primary mutation of the mitochondrial DNA.
19 adults with known mitochondrial mutation (MT) have been assessed with the Stanford Health Assessment Questionnaire 20-item Disability Index (HAQ-DI), the Symptom Check List-90-Revised (SCL-90-R), the Beck Depress...
We report an unusual case of juvenile ischaemic stroke syndrome associated with the A8344G mutation in tRNA(Lys) gene of mitochondrial DNA. The clinical phenotype of patient was typical for MELAS (mitochondrial ecephalomyapathy with lactate acidosis and stroke like episodes). The MELAS has been related to mutation A3243G in most cases, but some oth...
BackgroundMitochondrial disorders are underdiagnosed and the variable symptomatology, which is not always explained by the medical test
results and often includes mental symptoms, can mimic somatoform disorder.
MethodCase report of a woman with multisystemic symptomatology arising from mitochondrial dysfunction diagnosed as somatoform disorder,
wh...
We summarize those epilepsies, in which genetic testing has clinical significance. Different types of genetic tests are presented. Na-channel epilepsies include different clinical entities, the exact genetic diagnosis is relevant in the prognosis, genetic counseling, as well in the therapeutic decision--as Na-channel blockers may worsen them. Molec...
Although much is known about the protective effect of acute estrogen therapy in cerebral ischemia, relatively little is known about the importance of apoptosis and cerebral plasticity in this mechanism. In this work 10 min global cerebral ischemia was produced by transient bilateral carotid occlusion in 4-month-old ovariectomized female gerbils. In...
Permanent bilateral carotid occlusion is a well known cerebral hypoperfusion model in rats. The aim of our study was to investigate the different stages of vascular reaction by detecting changes in the extracellular martix proteins and to examine their relationship to angiogenesis after occlusion. Experiments were performed on adult male rats. Brai...
The authors summarize the pathomechanism of the myelination process, the clinical, radiological and the genetical aspects of the leukodystrophies, as in 18q deletion syndrome, adrenoleukodysrtophy, metachromatic leukodystrophy, Pelizaeus-Merzbacher leukodystrophy, Alexander disease and olivo-ponto-cerebellar atrophy (OPCA).
Although much is known about the protective effect of acute estrogen therapy in cerebral ischemia, relatively little is known about its effect on functional outcome at different ages. The impact of age is, however, important on the efficacy of steroids in the central nervous system. We investigated whether a single dose of estradiol pre-treatment w...
The A3243G mutation in the mitochondrial tRNALeu (UUR) gene is one of the most common causes of mitochondrial DNA related disorders. Originally it was described in MELAS syndrome
(Mitochondrial Encephalomyopathy, Lactic acidosis, Stroke-like episodes), later it had been found to be associated with various
phenotypes. In our study the mutation frequ...
To investigate whether the single nucleotide polymorphisms (SNPs) of the LOXL1 gene associated with exfoliation syndrome (XFS) and exfoliative glaucoma (XFG) are different in XFS/XFG patients with and without cardiovascular disease (CVD); and to compare the allele frequencies in XFS/XFG with those in ischemic cerebrovascular disease (stroke), in th...
Accumulation of cathepsin D immunoreactive lysosomes correlates with tissue pathology in sporadic Creutzfeldt-Jakob disease (CJD) brains. The C-to-T transition within exon 2 of the cathepsin D (CTSD) gene is associated with altered enzymatic activity. Possession of the TT genotype is a risk factor for variant CJD. To verify the association between...
We report a novel heteroplasmic mitochondrial tRNA(Lys) mutation associated with dystonia, stroke-like episodes, sensorineural hearing loss and epilepsy in a Hungarian family.
A 16-year-old boy, his brother and mother were investigated. Thorough clinical investigation as well as electrophysiological, neuroradiological and myopathological examinatio...
Autoimmune myasthenia gravis is a disorder with a complex pathomechanism in which sex hormones, in particular oestrogen, have long been considered to play a role. Here we report the result of a case-control study which evaluated the association of two oestrogen receptor alpha gene polymorphisms with myasthenia gravis in Caucasian patients. PvuII (r...