Mutation spectrum of the SCN1A gene in a Hungarian population with epilepsy.

PURPOSE: The vast majority of mutations responsible for epilepsy syndromes such as genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome (DS) occur in the gene encoding the type 1 alpha subunit of neuronal voltage-gated sodium channel (SCN1A). METHODS: 63 individuals presenting with either DS or GEFS + syndrome phenotype were screened for SCN1A gene mutation using Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). RESULTS: Our research study identified 15 novel pathogen mutations in the SCN1A gene of which 12 appeared to be missense mutations with addition of two frameshift-deletions and one in-frame deletion. The distribution of clinical phenotypes in patients carrying SCN1A mutations was as follows: twelve patients had classical DS, three patients had GEFS + syndrome and two relatives of DS patients were suffering from febrile seizures. CONCLUSIONS: Our study highlights the phenotypic and genotypic heterogeneities of DS and GEFS + with the important aim of gaining a deeper understanding of SCN1A-related disorders. This study also represents the first genetic analysis of the SCN1A gene in a Hungarian cohort with the DS and GEFS + syndrome phenotype.

[Neuroacanthocytosis diagnosis with new generation whole exome sequencing]. / Neuroacanthocytosis diagnózisa új generációs exom-szekvenálással.

In a patient with marked symptoms of Huntington disease after the huntingtin testing, which gave normal result, a whole exome sequencing (WES) has been performed based on an international collaboration. A homozygous G>A nucleotid change in the exon 34 of the VPS13A gene has been detected with WES, a mutation resulting in a premature stop codon at the position 1301. This change is a known pathogenic mutation. The aim of this article is to draw attention on the importance of the WES in the diagnosis of rare neurological diseases without any specific symptoms. Orv Hetil. 2017; 158(42): 1681-1684.

[A8344G mitochondrial DNA mutation observed in two generations]. / Két generációban megfigyelheto mitokondriális DNS A8344G mutáció.

This article presents the case of a 62-year-old mother and her 41-year-old daughter, who have had severe neurological symptoms for a few decades. After a long investigation period the definite diagnosis of MERRF syndrome was confirmed. After DNA isolation from our patient's blood sample we examined the mitochondrial DNA with direct sequencing. An adenine-guanine substitution was detected in the tRNA gene at position 8344, based on the sequence ferogram the heteroplasmy was over 90%. The clinical phenotype was not clearly characteristic for MERRF syndrome, adult-onset and lipomas are not typical in this disease. In our case report we would like to draw attention to the great phenotypic variation of the mitochondrial diseases and we emphasize that these disorders are underdiagnosed in Hungary even today. Orv. Hetil., 2017, 158(12), 468-471.

[Catch-22? Wide variety of phenotypes associated with the chromosome 22q11 deletion syndrome in two patients]. / A 22-es csapdája? A 22q11 kromoszóma deletiós szindróma változatos klinikai megjelenése két eset kapcsán.

The chromosome 22q11 deletion syndrome may present with a variety of phenotypes. Its symptoms generally include a characteristic facial dysmorphisms and multiplex developmental disorders. Fluorescence in situ hybridization is the current method of choice for the diagnosis if typical multiple defects and/or symptoms are present. The authors present the history of two patients who were followed-up for minor anomalies and various developmental disorders for several years in the genetic counseling office of the authors, but definitive diagnosis was not established. However, when DNA samples of the two patients were recently tested with array comparative genome hybridization, a diagnostic method which has already been used in their institute for several years, the results indicated deletion of the 11.2 region on the long arm of chromosome 22 in both patients. The authors draw attention to the incidence and wide phenotypic spectrum of the chromosome 22q11 deletion syndrome, and show that its identification can be aided with the novel molecular cytogenetic method available in their laboratory.

[Genetic testing in hereditary spastic paraplegia]. / Herediter spasticus paraplegia genetikai vizsgálata.

INTRODUCTION: Hereditary spastic paraplegia is the overall term for clinically and genetically diverse disorders characterized with progressive and variable severe lower extremity spasticity. The most common causes of autosomal dominantly inherited hereditary spastic paraplegias are different mutations of the spastin gene with variable incidence in different ethnic groups, ranging between 15-40%. Mutations in the spastin gene lead to loss of spastins function, causing progressive neuronal failure, which results in axon degeneration finally. AIM: The molecular testing of spastin gene is available in the institution of the authors since January, 2014. The experience gained with the examination of the first eleven patients is described in this article. METHOD: After polymerase chain reaction, Sanger sequencing was performed to examine the 17 exons of the spastin gene. Multiplex ligation-dependent probe amplification was performed to detect greater rearrangements in the spastin gene. Eight of the patients were examined in the genetic counseling clinic of the authors and after detailed phenotype assessment spastin gene testing was obtained. The other three patients were referred to the laboratory from different outpatient clinics. RESULTS: Out of the 11 examined patients, four different pathogenic mutations were found in 5 patients. CONCLUSIONS: The first Hungarian data, gained with the examination of spastin gene are presented in this article. The five patients, in whom mutations were detected, represent 45.5% of all tested patients with hereditary spastic paraplegia, which is similar to those published in the international literature. Molecular testing and subsequent detailed genotype-phenotype correlations of the Hungarian patients may serve valuable new information about the disease, which later on may influence our therapeutic possibilities and decisions.