Genetikai kórképek hazai roma populatióban = Genetic disorders in Romani population

1. Biotinidase defektusos újszülöttek szűrése a betegek molekuláris genetikai analysise magyar kaukazoid és roma populatioban.Eredmények:Hazai vizsgálatok: 58 családban vizsgáltuk a specifikus biotinidáz enzymaktivitást a kiszűrt enzymhiányos családokban, Wolf és mtsai. (1983) módszerével, fél Magyarországi újszülöttpopulációban, kiemelve a hazai roma populatio érintettségét. Molekuláris genetikai mutációs vizsgálatok polymerase láncreakció/SSCP analysissel történtek. A betegek 60 %-a roma populációhoz tartozik. Öt családban fordult elő az 1595C>T (T532M) mutáció, amely founder (alapító)mutációnak felel meg, utóbbi eredeti megállapítás, általánosítás roma populatiora. További 1 biotinidáz defektusos betegnél a 15 95C-T /Q456H és egy másiknál kettős heterozygotaság volt kimutatható, így 511G>A és 1330G>C ( A171CT/D444H). Egy másik beteg részleges enzymhiánnyal heterozygota genotípusú volt 1595C>T (T532M) és heterozygota 13300 GyC (D444H) pontmutatióra. Egy beteg biotinidáz enzymaktivitása nulla volt, aki homozygota mutánsnak bizonyult 1568CyT (T532M)-re. 2. A galaktokináz (GALK1) gén P28T mutáció incidenciája galactokinase hiányos roma betegekben Európában.Összesen 803 nem rokon roma érintett beteget vizsgáltunk Bulgáriában, Magyarországon és Spanyolországban, az össz. génhordozó ráta 1:47-nek adódott. Munkacsoportunk által detektált: P28T mutáció founder mutációnak minősíthető a GALK1 génben. | 1.Neonatal screening for biotinidase deficiency in Hungary was made in 58 families with Wolf et. al. (1983) method. PCR/SSCP analysis was carried out. The patient?s 60% belong to Roma population. As founder mutation 1595C>T (T532M) mutation has been proven. 2.Mutation analysis of galaktokinase (GALK 1) gene in Rom. population. The P28T mutation in GALK 1 gene accounts for galaktokinase deficiency as founder mutation. 3.Population molecular genetic investgation for cystic fibrosis in C. and R. population. (Tiszalök, Tiszadada, Tiszanánás). The delta F 508 mutation occurred in 43%, with 0,144 homosygous index (HI), against of 50% with 0,127 HI in C. 4.Population genetic analysis of Y chromosome in R. population. Y STR systems were detected by gen RES DYS plex-1 and plex 2 cits,with Y markers DYS 19, DYS 389?in 201 C. and 196 R. The 2 Hungarian R. pop. were different. 5.Relevant pointmutations and polymorphysms for susceptibility for coronaria sclerosis in R. population, with light sicler (5-10 MTHFR, C677T polymorphism, ACE insertion and deletion polymorphism ID), plasminogen gene activator inhibitor (PAI 4/5) polymorphysm. Results: PAI4 allele was significantly more frekvent, while PAI5 and MTHFR C667T mutation were decreased. 6.Facioscapulohumeral dystrophy FSHD(Spinal Muscular Atrophy) and congenital myasthenia syndrome were analysed in Rom. population with PCR/RFLP. The 1267 delG (guanine deletion) as founder mutation of Rom. minority was proven

Herediter neuromusculáris betegségek szűrése molekuláris genetikai módszerekkel hazai roma populációban = Screening of hereditary neuromuscular disorders in the Roma population living in Hungary

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. Hereditary disorders of the Roma populations are known for a long time. The genetic background of these diseases has been established by extensive molecular genetic studies. The Romas represent 6% of the Hungarian population and live under extremely bad health conditions. Therefore, our aim was to map the incidence of the hereditary neuromuscular disorders among the Hungarian Roma population. Moreover, we intended to provide proper information, genetic counseling and possible prevention strategies for the families at risk, which should represent a primer task in public health. Because of our experience in neuromuscular disorders, we choose six, frequent, autosomal recessive disorders for these clinical and genetic studies: hereditary motor and sensory neuropathy type Lom (HMSNL), hereditary motor and sensory neuropathy type Russe (HMSNR), congenital cataracts facial dysmorphism syndrome (CCFDN), limb-girdle muscular dystrophy 2C (LGMD2C), congenital myasthenic syndrome (CMS) and spinal muscular atrophy (SMA). Following identification of the founder mutations, the possibility of prenatal diagnosis and carrier screening for family members will contribute to the decrease of the recurrence risk for these severe, mostly untreatable disorders

A de novo atypical ring sSMC(22) characterized by array CGH in a boy with cat-eye syndrome.

BACKGROUND: Microduplications 22q11 have been characterized as a genomic duplication syndrome mediated by nonallelic homologous recombination between region-specific low-copy repeats. Here we report on a 19 years old boy with intellectual disability having an unexpected structurally complex ring small supernumerary marker chromosome (sSMC) originated from a larger trisomy and a smaller tetrasomy of proximal 22q11 harboring additional copies of cat eye syndrome critical regions genes. RESULTS: PRINCIPAL CLINICAL FEATURES WERE: anorectal and urogenital malformations, total anomalous pulmonary venous return with secundum ASD, hearing defect, preauricular pits, seizure and eczema. The proband also presented some rare or so far not reported clinical findings such as hyperinsulinaemia, severe immunodeficiency and grave cognitive deficits. Chromosome analysis revealed a mosaic karyotype with the presence of a small ring-like marker in 60% of cells. Array CGH detected approximately an 1,2 Mb single and a 0,2 Mb double copy gain of the proximal long arm of chromosome 22. The 1,3 Mb intervening region of chromosome 22 from centromere to the breakpoints showed no copy alteration. The karyotype of the patient was defined as 47,XY,+mar[60]/46,XY[40].ish idic r(22)(q11.1.q11.21) x 4.arr 22q11(17,435, 645-18,656,678) x 3,(17,598,642-17,799,783) x 4 dn. CONCLUSIONS: The present report is the first one with a detailed description of clinical presentation in a patient carrying an atypical size ring sSMC (22) analyzed by array CGH. The specialty of the finding is emphasized by the fact that although the patient had a mosaic sSMC and the amplified region was smaller than in typical cat eye syndrome cases, the clinical presentation was severe

A spinalis izomatrophiát meghatározó survival motoneuron gének kvantitatív analízise = Quantitative analysis of the genes determining spinal muscular atrophy

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. On the other hand, the copy number of SMN2 affects the amount of SMN protein produced and the severity of the SMA phenotype. SMN gene dosage analysis can determine the copy number of SMN1 to detect carriers and patients heterozygous for the absence of SMN1 exon 7. This study provides copy number estimation of SMN1 gene by real-time PCR technique in 56 SMA type I., II., III. patients, 159 parents and healthy relatives and in 152 undefined SMA patients. Among the family members, 91 carriers have been detected and in 56 patients homozygous deletion of SMN1 exon 7 has been confirmed. Moreover, in 12 patients compound heterozygosity of SMN1 exon 7 mutation has been detected, thus providing the possible diagnosis of SMA. In 94 patients, copy number of SMN2 has also been evaluated and a good correlation has been found with the phenotype of the disease. Due to the genetic complexity and the high carrier frequency, accurate risk assessment and genetic counselling are particularly important for the families. These new results provide improvement of the diagnostic service in SMA in Hungary with focus on proper genetic counselling and possible enrolment of the patients in future therapeutic interventions

Molecular cytogenetic analysis of Xq critical regions in premature ovarian failure.

BACKGROUND: One of the frequent reasons for unsuccessful conception is premature ovarian failure/primary ovarian insufficiency (POF/POI) that is defined as the loss of functional follicles below the age of 40 years. Among the genetic causes the most common one involves the X chromosome, as in Turner syndrome, partial X deletion and X-autosome translocations. Here we report a case of a 27-year-old female patient referred to genetic counselling because of premature ovarian failure. The aim of this case study to perform molecular genetic and cytogenetic analyses in order to identify the exact genetic background of the pathogenic phenotype. RESULTS: For premature ovarian failure disease diagnostics we performed the Fragile mental retardation 1 gene analysis using Southern blot technique and Repeat Primed PCR in order to identify the relationship between the Fragile mental retardation 1 gene premutation status and the premature ovarion failure disease. At this early onset, the premature ovarian failure affected patient we detected one normal allele of Fragile mental retardation 1 gene and we couldn't verify the methylated allele, therefore we performed the cytogenetic analyses using G-banding and fluorescent in situ hybridization methods and a high resolution molecular cytogenetic method, the array comparative genomic hybridization technique. For this patient applying the G-banding, we identified a large deletion on the X chromosome at the critical region (ChrX q21.31-q28) which is associated with the premature ovarian failure phenotype. In order to detect the exact breakpoints, we used a special cytogenetic array ISCA plus CGH array and we verified a 67.355 Mb size loss at the critical region which include total 795 genes. CONCLUSIONS: We conclude for this case study that the karyotyping is definitely helpful in the evaluation of premature ovarian failure patients, to identify the non submicroscopic chromosomal rearrangement, and using the array CGH technique we can contribute to the most efficient detection and mapping of exact deletion breakpoints of the deleted Xq region

Izomdystrophiák differenciál-diagnosztikai vizsgálata molekuláris genetikai, valamint immunhisztokémiai és immunoblot analízisek segítségével = Differential diagnostic study of muscle dystrophies by molecular genetic, immunohystochemical and Western-blot analyses

A DMD/BMD betegségben célul tűzték ki a cDNS próbák alkalmazását a hordozósági státusz vizsgálatára és a deléciók pontos méretének meghatározására. Az újonnan bevezetett MLPA módszer segítségével a teljes dystrophin gén feltérképezésére, bizonyos pont mutációk kiszűrésére, a deléciók és duplikációk pontos analízisére, továbbá a hordozóság gyors szűrésére is vállalkozhattak. Összesen 120 beteg és 89 női hozzátartozó molekuláris analízisét végezték el a pályázat támogatásával. Az FSHD betegségben a komplex genetikai háttér miatt szükséges a molekuláris diagnosztikus kritériumok finomítása. A betegség hátterében álló epigenetikus változások kulcsfontosságúak lehetnek fenotípus kialakulásában. A betegség pathomechanizmusában a D4Z4 szekvenciáktól proximálisan elhelyezkedő gének megváltozott transzkripciójának van szerepe, amelynek vizsgálatára metilációs analízist alkalmaztak. A klinikai diagnózis megerősítésére összesen 90 beteg és 46 tünetmentes hozzátartozó DNS mintáját analizálták. Az LGMD betegségcsoport a betegek differenciál-diagnosztikája jelenleg csak specifikus fehérjedetektálási módszerekkel lehetségesek. Ezeket a módszereket alkalmazták azokban az esetekben, ahol az FSHD és DMD/BMD molekuláris genetikai vizsgálata negatív volt. A vizsgálati periódusban 122 beteg izombiopsziás mintája érkezett, ebből 56 esetben immunhisztokémiai, míg 20 esetben kiegészítő western blot analízis történt. További, DNS szintű analízisek 14 esetben azonosították a patogén mutációt. | The first aim of the study was to introduce cDNA probes for the analysis of DMD/BMD in order to detect carrier status and exact deletion borders. Additionally, the new MLPA technique was first introduced by us in Hungary and enabled the detection of the entire dystrophin gene with highlights on specific pointmutations, exact analysis of the deletions and duplications and moreover, on efficient screening of the carrier status. During the project, 120 affected persons and 89 female relatives were screened. In case of the FSHD molecular genetic criteria have to be improved because of the complexity of the disorder. Epigenetic influences may play a crutial role in modulating phenotype. Altered transcriptional activities of neighbouring genes proximal to the D4Z4 sequences have a key place in the pathomechanism, therefore, this effect was studied by methylation analysis. For confirmation of the clinical diagnosis 90 patients and 46 asymptomatic family members were genetically nalysed. The differential diagnosis of the heterogenous group of LGMD requires at first the specific analysis of the dystrophin-associated glycoproteins. This was used in the case of patients where the establishment of the genetic diagnosis of DMD/BMD or FSHD failed. Muscle biopsies and blood samples of 122 patients were sent to the laboratory; in total 56 immunohistochemical and 20 Western blot analyses have been performed. In 14 patients the exact pathogenic mutation has been identified by DNA sequencing

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