Publications by authors named "Agnes Herczegfalvi"

Fukutin-related protein (FKRP, MIM ID 606596) variants cause a range of muscular dystrophies associated with hypo-glycosylation of the matrix receptor, α-dystroglycan. These disorders are almost exclusively caused by homozygous or compound heterozygous missense variants in the gene that encodes a ribitol phosphotransferase. To understand how seemingly diverse missense mutations may contribute to disease, we examined the synthesis, intracellular dynamics, and structural consequences of a panel of missense mutations that encompass the disease spectrum.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Objective: Genetic diagnosis and mutation identification are now compulsory for Duchenne (DMD) and Becker muscular dystrophies (BMD), which are due to dystrophin () gene mutations, either for disease prevention or personalized therapies. To evaluate the ethnic-related genetic assortments of mutations, which may impact on DMD genetic diagnosis pipelines, we studied 328 patients with DMD and BMD from non-European countries.

Methods: We performed a full DMD mutation detection in 328 patients from 10 Eastern European countries (Poland, Hungary, Lithuania, Romania, Serbia, Croatia, Bosnia, Bulgaria, Ukraine, and Russia) and 2 non-European countries (Cyprus and Algeria).

View Article and Find Full Text PDF

Several inborn errors of metabolism show cutis laxa as a highly recognizable feature. One group of these metabolic cutis laxa conditions is autosomal recessive cutis laxa type 2 caused by defects in v-ATPase components or the mitochondrial proline cycle. Besides cutis laxa, muscular hypotonia and cardiac abnormalities are hallmarks of autosomal recessive cutis laxa type 2D (ARCL2D) due to pathogenic variants in ATP6V1A encoding subunit A of the v-ATPase.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Background: Recent short-term clinical trials in patients with Duchenne Muscular Dystrophy (DMD) have indicated greater disease variability in terms of progression than expected. In addition, as average life-expectancy increases, reliable data is required on clinical progression in the older DMD population.

Objective: To determine the effects of corticosteroids on major clinical outcomes of DMD in a large multinational cohort of genetically confirmed DMD patients.

View Article and Find Full Text PDF

Background: Publication of comprehensive clinical care guidelines for Duchenne muscular dystrophy (DMD) in 2010 was a milestone for DMD patient management. Our CARE-NMD survey investigates the neuromuscular, medical, and psychosocial care of DMD patients in Europe, and compares it to the guidelines.

Methods: A cross-sectional survey of 1677 patients contacted via the TREAT-NMD patient registries was conducted using self-report questionnaires in seven European countries.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF

Introduction: Hereditary hyperekplexia is a neurological disorder characterized by excessive startle responses with violent jerking to noise or touch, stiffening of the trunk and limbs, clenching of the fists and attacks of a high-frequency trembling. Hyperekplexia has a heterogeneous genetic background with several identified causative genes and demonstrates both dominant and recessive inheritance. Mutations in the glycine receptor alpha 1 subunit gene occur in about 30 percent of hyperekplexia cases.

View Article and Find Full Text PDF

Background: Behr's syndrome is a classical phenotypic description of childhood-onset optic atrophy combined with various neurological symptoms, including ophthalmoparesis, nystagmus, spastic paraparesis, ataxia, peripheral neuropathy and learning difficulties.

Objective: Here we describe 4 patients with the classical Behr's syndrome phenotype from 3 unrelated families who carry homozygous nonsense mutations in the gene encoding a protein involved in mitochondrial translation.

Methods: Whole exome sequencing was performed in genomic DNA and oxygen consumption was measured in patient cell lines.

View Article and Find Full Text PDF

Spinal muscular atrophy (SMA) is an autosomal recessive genetic disorder characterised by the degeneration of motor neurons and progressive muscle weakness. It is caused by homozygous deletions in the survival motor neuron gene on chromosome 5. SMA shows a wide range of clinical severity, with SMA type I patients often dying before 2 years of age, whereas type III patients experience less severe clinical manifestations and can have a normal life span.

View Article and Find Full Text PDF

Duchenne muscular dystrophy (DMD) is an X-linked genetic disease, caused by the absence of the dystrophin protein. Although many novel therapies are under development for DMD, there is currently no cure and affected individuals are often confined to a wheelchair by their teens and die in their twenties/thirties. DMD is a rare disease (prevalence <5/10,000).

View Article and Find Full Text PDF

Drug trials in children engage with many ethical issues, from drug-related safety concerns to communication with patients and parents, and recruitment and informed consent procedures. This paper addresses the field of neuromuscular disorders where the possibility of genetic, mutation-specific treatments, has added new complexity. Not only must trial design address issues of equity of access, but researchers must also think through the implications of adopting a personalised medicine approach, which requires a precise molecular diagnosis, in addition to other implications of developing orphan drugs.

View Article and Find Full Text PDF

Unlabelled: Autosomal dominant facioscapulohumeral muscular dystrophy (FSHD) is caused by contraction of the D4Z4 repeat region on 4q35. In addition, epigenetic modifying factors play a role in the complex pathomechanism of the disease.

Aims: Introduction of a new diagnostic panel in Hungary for the extended molecular analysis of the disease which also provides new insights into the pathomechanism.

View Article and Find Full Text PDF

Unlabelled: Pompe's disease is an autosomal recessive disease caused by deficiency of acid-alpha-glucosidase.

Aims And Methods: Authors analyzed the phenotype of 11 Hungarian patients with Pompe's disease and evaluated clinical parameters and response to enzyme replacement therapy during a long-term follow-up in 8 patients.

Results: One patient with atypical infantile form presented with cardiomyopathy and a very slow progression of motor deficits; after 2 years of enzyme replacement therapy no disability was present at the age 6 years.

View Article and Find Full Text PDF

Mutations in the nebulin gene are the main cause of autosomal recessive nemaline myopathy, with clinical presentations ranging from mild to severe disease. We have previously reported a nonspecific distal myopathy caused by homozygous missense mutations in the nebulin gene in six Finnish patients from four different families. Here we describe three non-Finnish patients in two unrelated families with distal nemaline myopathy caused by four different compound heterozygous nebulin mutations, only one of which is a missense mutation.

View Article and Find Full Text PDF

Spinal muscular atrophy (SMA) is one of the most common autosomal recessive diseases, affecting approximately one in 10,000 live births and with a carrier frequency of approximately one in 35. The disease is caused by a deficiency of the ubiquitous protein survival of motor neuron (SMN), which is encoded by the SMN1 and SMN2 genes. Due to a single nucleotide polymorphism in exon 7, SMN2 produces less full-length transcript than SMN1 and cannot prevent neuronal cell death at physiologic gene dosages.

View Article and Find Full Text PDF

The authors discuss the clinical and molecular genetic aspects of genetically determined neuromuscular disorders of some Roma families living in Hungary. Among the autosomal recessively inherited spinal muscular atrophic (SMA) group, 8 Caucasian children had the typical 7-8 exonal deletions of the SMA gene, but only 2 patients belonged to the Roma population. There was no difference in the molecular genetic findings among the Caucasian and the Roma SMA patients.

View Article and Find Full Text PDF

A comprehensive study of the Hungarian Duchenne/Becker muscular dystrophy (DMD/BMD) families is presented. Deletions in the hot spots regions were identified by multiplex PCR, whereas rare mutations were detected by Southern blot and multiplex ligation-dependent probe amplification (MLPA) techniques. DMD/BMD disease was confirmed and exact deletion borders were determined in 19 out of 135 affected males using multiplex PCR.

View Article and Find Full Text PDF

Recent medical genetic research has identified a number of novel, or previously known, but rare conditions, caused by private founder mutations. The Finnish and Ashkenazi Jew populations provide the best examples for identifying genes in unique genetic disorders. In these populations, research efforts and high-level medical services resulted in intense improvements of medical care and in organization of population-based screening programs.

View Article and Find Full Text PDF

Objective And Background: Severe myoclonic epilepsy in infancy (SMEI; Dravet's syndrome) is a malignant epilepsy syndrome characterized by prolonged febrile hemiconvulsions or generalized seizures starting in the first year of life. Later on myoclonic, atypical absence, and complex partial seizures appear. When one of these seizure forms is lacking the syndrome of borderline SMEI (SMEB) is defined.

View Article and Find Full Text PDF

Congenital myasthenic syndromes (CMS) are clinically and genetically heterogeneous inherited disorders characterized by impaired neuromuscular transmission. Mutations in the acetylcholinesterase (AChE) collagen-like tail subunit gene (COLQ) cause synaptic basal-lamina associated CMS with end-plate AChE deficiency. Here we present the clinical and molecular genetic findings of 22 COLQ-mutant CMS patients, carrying a total of 20 different COLQ mutations, 11 of them had not previously been reported.

View Article and Find Full Text PDF

Duchenne/Becker muscular dystrophy is a severe, recessive, X-linked neuromuscular disease with an incidence of 1/3500 (Duchenne type) and 1/30,000 (Becker type) in newborn boys. The gene responsible for the Duchenne/Becker muscular dystrophy phenotype is located at Xp21 and its 427 kD protein product is called dystrophin. Deletions, point mutations and rarely duplications can occur almost anywhere in the DMD gene, which makes the molecular diagnosis difficult.

View Article and Find Full Text PDF

Dok ('downstream-of-kinase') family of cytoplasmic proteins play a role in signalling downstream of receptor and non-receptor phosphotyrosine kinases. Recently, a skeletal muscle receptor tyrosine kinase (MuSK)-interacting cytoplasmic protein termed Dok-7 has been identified. Subsequently, we and others identified mutations in DOK7 as a cause of congenital myasthenic syndromes (CMS), providing evidence for a crucial role of Dok-7 in maintaining synaptic structure.

View Article and Find Full Text PDF

Objective: To evaluate the efficacy and tolerability of levetiracetam in children with drug resistant epilepsy from a retrospective study.

Methods: We report the result of a study of 85 pediatric patients (mean 10.5 years, range: 1-24) with refractory generalized and focal epilepsy, who received levetiracetam as add-on treatment.

View Article and Find Full Text PDF