Agnes Herczegfalvi

Mutation history of the Roma/Gypsies

The 8-10 million European Roma/Gypsies are a founder population of common origins that has subsequently split into multiple socially divergent and geographically dispersed Gypsy groups. Unlike other founder populations, whose genealogy has been extensively documented, the demographic history of the Gypsies is not fully understood and, given the lack of written records, has to be inferred from current genetic data. In this study, we have used five disease loci harboring private Gypsy mutations to examine some missing historical parameters and current structure. We analyzed the frequency distribution of the five mutations in 832-1,363 unrelated controls, representing 14 Gypsy populations, and the diversification of chromosomal haplotypes in 501 members of affected families. Sharing of mutations and high carrier rates supported a strong founder effect, and the identity of the congenital myasthenia 1267delG mutation in Gypsy and Indian/Pakistani chromosomes provided the best evidence yet of the Indian origins of the Gypsies. However, dramatic differences in mutation frequencies and haplotype divergence and very limited haplotype sharing pointed to strong internal differentiation and characterized the Gypsies as a founder population comprising multiple subisolates. Using disease haplotype coalescence times at the different loci, we estimated that the entire Gypsy population was founded approximately 32-40 generations ago, with secondary and tertiary founder events occurring approximately 16-25 generations ago. The existence of multiple subisolates, with endogamy maintained to the present day, suggests a general approach to complex disorders in which initial gene mapping could be performed in large families from a single Gypsy group, whereas fine mapping would rely on the informed sampling of the divergent subisolates and searching for the shared genomic region that displays the strongest linkage disequilibrium with the disease.

The TREAT‐NMD Duchenne Muscular Dystrophy Registries: Conception, Design, and Utilization by Industry and Academia

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). Even the largest countries do not have enough affected patients to rigorously assess novel therapies, unravel genetic complexities, and determine patient outcomes. TREAT‐NMD is a worldwide network for neuromuscular diseases that provides an infrastructure to support the delivery of promising new therapies for patients. The harmonized implementation of national and ultimately global patient registries has been central to the success of TREAT‐NMD. For the DMD registries within TREAT‐NMD, individual countries have chosen to collect patient information in the form of standardized patient registries to increase the overall patient population on which clinical outcomes and new technologies can be assessed. The registries comprise more than 13,500 patients from 31 different countries. Here, we describe how the TREAT‐NMD national patient registries for DMD were established. We look at their continued growth and assess how successful they have been at fostering collaboration between academia, patient organizations, and industry.

Nemaline myopathy caused by mutations in the nebulin gene may present as a distal myopathy

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. One of the mutations has previously been identified in one family with the severe form of nemaline myopathy. We conclude that nemaline myopathy and distal myopathy caused by nebulin mutations form a clinical and histological continuum. Nemaline myopathy should be considered as a differential diagnosis in patients presenting with an early-onset predominantly distal myopathy.

Dystrophin gene analysis in Hungarian Duchenne/Becker muscular dystrophy families - Detection of carrier status in symptomatic and asymptomatic female relatives

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. Additional exons involved as well as rare exon deletions were identified by MLPA in 71 male patients, whereas duplications were observed in seven patients. In two DMD patients, the entire dystrophin gene and adjacent genes were deleted. Out of the 95 female relatives, 41 proved to be carriers, including three manifesting carrier females. Using MLPA method, a large portion of the Hungarian DMD/BMD patients and their female relatives were exactly genotyped. For the first time, the incidence and prevalence of asymptomatic and symptomatic female carriers in Hungary was estimated.

Guidance in Social and Ethical Issues Related to Clinical, Diagnostic Care and Novel Therapies for Hereditary Neuromuscular Rare Diseases: "Translating" the Translational.

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. It is against this background of change and complexity that the Project Ethics Council (PEC) was established within the TREAT-NMD EU Network of Excellence. The PEC is a high level advisory group that draws upon the expertise of its interdisciplinary membership which includes clinicians, lawyers, scientists, parents, representatives of patient organisations, social scientists and ethicists. In this paper we describe the establishment and terms of reference of the PEC, give an indication of the range and depth of its work and provide some analysis of the kinds of complex questions encountered. The paper describes how the PEC has responded to substantive ethical issues raised within the TREAT-NMD consortium and how it has provided a wider resource for any concerned parent, patient, or clinician to ask a question of ethical concern. Issues raised range from science related ethical issues, issues related to hereditary neuromuscular diseases and the new therapeutic approaches and questions concerning patients rights in the context of patient registries and bio-banks. We conclude by recommending the PEC as a model for similar research contexts in rare diseases.

Behr's Syndrome is Typically Associated with Disturbed Mitochondrial Translation and Mutations in the C12orf65 Gene.

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 C12orf65 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. Results We detected 2 different homozygous C12orf65 nonsense mutations in 4 patients with a homogeneous clinical presentation matching the historical description of Behr’s syndrome. The first symptom in all patients was childhood-onset optic atrophy, followed by spastic paraparesis, distal weakness, motor neuropathy and ophthalmoparesis. Conclusions We think that C12orf65 mutations are more frequent than previously suggested and screening of this gene should be considered not only in patients with mitochondrial respiratory chain deficiencies, but also in inherited peripheral neuropathies, spastic paraplegias and ataxias, especially with pre-existing optic atrophy.

Identification of a novel missense GLRA1 gene mutation in hyperekplexia: a case report

IntroductionHereditary 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.Case presentationIn this study, we report the case of a Hungarian boy whose abnormal movements, muscle stiffness and convulsions were first noted when he was 4 days old. Neurological and electrophysiological investigation suggested the clinical diagnosis of hyperekplexia.ConclusionsDirect sequencing of the coding regions and the flanking introns of the glycine receptor alpha 1 subunit gene revealed a novel heterozygous missense mutation (c.211A/T, p.Ile71Phe). Genetic screening of our patient’s family revealed that the clinically unaffected parents and sister do not carry the mutation, suggesting that the identified sequence change is a de novo mutation. Since hyperekplexia can have severe consequences, including sudden infant death due to laryngospasm and cardiorespiratory failure, identification of the causative genetic alteration(s) of the disease is high priority. Such knowledge is necessary for prenatal diagnosis, which would allow informed family planning and greater parental sensitivity to hyperekplexia 1-associated risks.

Role of associated alleles and hypomethylation status in the clinical expression of facioscapulohumeral muscular dystrophy

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. METHODS In total, DNA samples of 185 clinically diagnosed FSHD patients and 71 asymptomatic relatives were analyzed by EcoRI and BlnI restriction digestion and Southern blot technique with probe p13-E11. Further investigations of the 4q35 alleles associated with the FSHD phenotype utilized qA and qB probes and a restriction analysis of the proximal D4Z4 unit by detecting a G/C SNP and the methylation status. RESULTS From the patients analyzed 115 had the D4Z4 repeat contraction, whereas from 71 asymptomatic family members five harbored the pathogenic fragment size. In eight families, prenatal testing had to be offered with an outcome of four affected fetuses. Methylation test was performed in 31 genetically confirmed FSHD patients and hypomethylation status was detected in all cases. All the 115 confirmed patients had 4qA alleles with the G polymorphism. Translocation events between 4q35 and the homologous 10q26 regions were also detected. CONCLUSION Molecular diagnosis of FSHD became a routine approach in Hungary thus supporting the work of the clinicians, improving quality of life and genetic counseling of the affected families. The provided results from this research suggest that FSHD is associated with complex epigenetic disease mechanisms.

[Carrier detection in families affected by Duchenne/Becker muscular dystrophy].

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. Multiple polymerase chain reactions detect 95% of deletions in affected males [2, 4], but are not suitable for carrier detection in female relatives. Southern-blot analysis with six different cDNA probes covers the whole 14 kb dystrophin transcript and allows the detection of female carriers by comparing the intensity of the signals corresponding to the different exons. This method is time consuming compared to the newly introduced multiple ligation-dependent probe amplification method. Multiple ligation-dependent probe amplification is a method suitable for relative quantification of several DNA sequences in one reaction. The authors report results on 93 cases where the carrier status was analysed simultaneously by cDNA hybridisation and multiple ligation-dependent probe amplification technique. In 42 cases the carrier state was confirmed and in this carrier population the authors additionally detected two cases with duplication, two cases with one copy of the whole dystrophin gene and three manifest carrier females. On the basis of these results the MLPA technique, which has been newly introduced in Hungary, proved to be a sensitive and quick method for the detection of carrier state in the DMD/BMD disease. Moreover, the exact deletion or duplication border can be detected and as a result, prediction on the phenotype can be given. This will provide the right therapeutic intervention for the affected patients in the future.

S.P.59 Current care practice in Duchenne Muscular Dystrophy in Europe – results of the CARE-NMD cross-sectional survey

Abstract CARE-NMD is an EU-funded project to improve care for patients with Durchenne Muscular Dystrophy (DMD). The analysis of the current care practice is the first step to identify gaps and to plan specific measures such as training sessions for professionals and workshops for patients. For this purpose, a large cross-sectional patient-survey about the received care and quality of life of patients with DMD has been performed since September 2011 in seven European countries: Bulgaria, Czech Republic, Denmark, Germany, Hungary, Poland and the United Kingdom. A total of 1,677 patients with Duchenne Muscular Dystrophy have received questionnaires via the national patient registries. For the assessment of quality of care we defined outcome and process indicators. Outcome indicators include stage of the disease, age at loss of ambulation, ability to sit, number of hospitalisations, cardiac and pulmonary function and age at diagnosis. Process indicators comprise the frequency of medical assessments and received treatment, e.g. the use of corticosteroids, non-invasive ventilation and assistive devices. By March 31st 1,093 of 1,677 patients/families responded (66 percent). Response by country were: Bulgaria 45/73, Czech Republic 92/191, Denmark 92/131, Germany 440/545, Hungary 62/70, Poland 137/246, and for United Kingdom 223/421. Key findings about health status, received treatment, and quality of life of patients with DMD in Europe will be presented. This is the largest ever cross-sectional survey of the care and quality of life of people with DMD. The final results will provide detailed insight into the current situation of people with DMD in Europe and help to identify gaps to further improve the situation of affected patients and families.