Mitochondrial sequence variation in ancient horses from the Carpathian Basin and possible modern relatives.

Movements of human populations leave their traces in the genetic makeup of the areas affected; the same applies to the horses that move with their owners This study is concerned with the mitochondrial control region genotypes of 31 archaeological horse remains, excavated from pre-conquest Avar and post-conquest Hungarian burial sites in the Carpathian Basin dating from the sixth to the tenth century. To investigate relationships to other ancient and recent breeds, modern Hucul and Akhal Teke samples were also collected, and mtDNA control region (CR) sequences from 76 breeds representing 921 individual specimens were combined with our sequence data. Phylogenetic relationships among horse mtDNA CR haplotypes were estimated using both genetic distance and the non-dichotomous network method. Both methods indicated a separation between horses of the Avars and the Hungarians. Our results show that the ethnic changes induced by the Hungarian Conquest were accompanied by a corresponding change in the stables of the Carpathian Basin.

Novel heteroplasmic mutation in the anticodon stem of mitochondrial tRNA(Lys) associated with dystonia and stroke-like episodes.

OBJECTIVES: We report a novel heteroplasmic mitochondrial tRNA(Lys) mutation associated with dystonia, stroke-like episodes, sensorineural hearing loss and epilepsy in a Hungarian family. MATERIAL AND METHODS: A 16-year-old boy, his brother and mother were investigated. Thorough clinical investigation as well as electrophysiological, neuroradiological and myopathological examinations were performed. Molecular studies included the analysis of the DYT1, DDP1/TIMM8A (deafness-dystonia peptid-1) genes and mitochondrial DNA (mtDNA). RESULTS: The mtDNA analysis of the proband revealed a heteroplasmic A8332G substitution in the anticodon stem of the tRNA(Lys) gene. The mutation segregated in all affected family members. Besides this mutation 16 further mtDNA polymorphisms were detected. Complex I activity of the patient's fibroblast cultures showed decreased activity confirming mitochondrial dysfunction. CONCLUSION: The novel A8332G heteroplasmic mutation is most likely a new cause of dystonia and stroke-like episodes due to mitochondrial encephalopathy. The synergistic effect of the G8697A, A11812G and T10463C single nucleotide polymorphisms may modify the phenotype.

H1 tau haplotype-related genomic variation at 17q21.3 as an Asian heritage of the European Gypsy population.

In this study, we examine the frequency of a 900 kb inversion at 17q21.3 in the Gypsy and Caucasian populations of Hungary, which may reflect the Asian origin of Gypsy populations. Of the two haplotypes (H1 and H2), H2 is thought to be exclusively of Caucasian origin, and its occurrence in other racial groups is likely to reflect admixture. In our sample, the H1 haplotype was significantly more frequent in the Gypsy population (89.8 vs 75.5%, P<0.001) and was in Hardy-Weinberg disequilibrium (P=0.017). The 17q21.3 region includes the gene of microtubule-associated protein tau, and this result might imply higher sensitivity to H1 haplotype-related multifactorial tauopathies among Gypsies.

Effects of intranasal phototherapy on nasal mucosa in patients with allergic rhinitis.

RATIONALE: Rhinophototherapy has been shown to be effective in the treatment of allergic rhinitis. Considering that phototherapy with ultraviolet light (UV) induces DNA damage, it is of outstanding importance to evaluate the damage and repair process in human nasal mucosa. METHODS: We have investigated eight patients undergoing intranasal phototherapy using a modified Comet assay technique and by staining nasal cytology samples for cyclobutane pyrimidine dimers (CPDs), which are UV specific photoproducts. RESULTS: Immediately after last treatment Comet assay of nasal cytology samples showed a significant increase in DNA damage compared to baseline. Ten days after the last irradiation a significant decrease in DNA damage was observed compared to data obtained immediately after finishing the treatment protocol. Difference between baseline and 10 days after last treatment was not statistically significant. Two months after ending therapy, DNA damage detected by Comet assay in patients treated with intranasal phototherapy was similar with that of healthy individuals. None of the samples collected before starting intranasal phototherapy stained positive for CPDs. In all samples collected immediately after last treatment strong positive staining for CPDs was detected. The number of positive cells significantly decreased 10 days after last treatment, but residual positive staining was present in all the examined samples. This finding is consistent with data reported in skin samples after UV irradiation. Cytology samples examined two months after ending therapy contained no CPD positive cells. CONCLUSION: Our results suggest that UV damage induced by intranasal phototherapy is efficiently repaired in nasal mucosa.

Mitochondrial DNA control region analysis of a late Neolithic aurochs (Bos primigenius Boj. 1827) from the Carpathian Basin.

Bos primigenius, the wild aurochs is believed to be the ancestor of European domestic cattle, Bos taurus. The geography and climate of the Great Hungarian Plain were well suited for these large grazing animals in the Late Neolithic. Till now, there are just a few aurochs mtDNA fragments available from two geographically restricted area, the British Isles and Italy. To increase our knowledge about the genetics of the European aurochsen livestock, and to investigate the phylogenetic position of a late Neolithic aurochs, excavated from the Carpathian Basin, mitochondrial DNA was extracted from a fragment of corpus mandibulae using ancient-DNA techniques and a portion of mitochondrial hypervariable region was amplified by PCR. The resulting sequence was aligned with GenBank sequences of 11 aurochsen. Our new sequence is identical with the sequence of two British aurochs. The 6000-year-old Hungarian aurochs shows a mtDNA sequence pattern, that occurs only among 6-12,000-year-old North European aurochsen, and it does not occur among modern, domesticated cattle.

A simple and efficient method for PCR amplifiable DNA extraction from ancient bones.

A simple and effective modified ethanol precipitation-based protocol is described for the preparation of DNA from ancient human bones. This method is fast and requires neither hazardous chemicals nor special devices. After the powdering and incubating of the bone samples Dextran Blue was added as a carrier for removing the PCR inhibitors with selective ethanol precipitation. This method could eliminate the time-consuming separate decalcification step, dialysis, application of centrifugation-driven microconcentrators and the second consecutive PCR amplification. The efficiency of this procedure was demonstrated on ten 500-1200-year-old human bones from four different Hungarian burial sites. A mitochondrial specific primer pair was used to obtain sequence information from the purified ancient DNA. The PCR amplification, after our DNA extraction protocol, was successful from each of the 10 bone samples investigated. The results demonstrate that extraction of DNA from ancient bone samples with this new approach increases the success rate of PCR amplification.

Chemical reverse transformation of CHO-K1 cells induces changes in expression of a candidate tumour suppressor and of a gene not previously characterised as transformation related.

Chemical reverse transformation of CHO-K1 and other cells is a well-established phenomenon, in which oncogenically transformed cells re-acquire fibroblastoid morphology, contact inhibition and anchorage-dependent growth, in response to cyclic AMP and other agents. A limited number of changes in gene transcription and enzyme activity have been demonstrated to coincide with these morphological and physiological changes. We have used a partial differential display to identify four genes that are transcriptionally modulated in reverse transformation. One of these, encoding ribosomal protein S18, is transcriptionally suppressed, probably as a result of the detransforming process. Three others are transcriptionally activated. One has homology to NADH-ubiquinone oxidoreductase chain 4 protein, and is also probably changed as a result of the detransforming process. Another is homologous to a human sequence which encodes a 27 kDa protein, p27(BBP/eIF6), that is involved in the biogenesis of 60S ribosomal subunit, and in cell lines of epithelial origin binds to beta integrin. This has not previously been described as transformation-related, and could have a causative role in reverse transformation. The third has homology, with transcriptional or processing variations, to a human genomic sequence, a positional candidate for a tumour suppressor gene, encoding the Krit1 protein which interacts with the Ras-family GTPase Krev-1.

No mitochondrial haplotype was found to increase risk for Alzheimer's disease.

BACKGROUND: Seventy Alzheimer's disease (AD) patients and 80 age- and sex-matched controls were analyzed for mitochondrial mutations T4336C and A3397G, reported to be associated with AD, and for mutations T4216C/G13708A characteristic for a normal human haplotype associated with increased frequency of occurrence of some hereditary diseases. The distribution of apolipoprotein E (apoE) alleles was also analyzed. METHODS: Mitochondrial DNA was amplified by polymerase chain reaction, and the presence of mutations was detected by digestion with approximately chosen restriction endonucleases (restriction fragment length polymorphism). RESULTS: One patient and 2 controls were found to belong to the T4336C/T1630C haplotype. No A3397G mutant was detected. The T4216C/G13708A haplotype occurred at 5/70 and 5/80 frequency in the two groups. Prevalence of the apoE4 allele was significantly higher in AD patients (25%) than in the control group (8.1%). CONCLUSIONS: The T4336C/T16304C mutations were not found to associated with AD, and no predisposing mitochondrial haplotypes were found.

Apolipoprotein E polymorphism in Pick's disease and in Huntington's disease.

The polymorphism of apolipoprotein E (apoE) has been recognized as a genetic risk factor in different neurodegenerative disorders, with or without tau protein- related neuropathology, but few published epidemiological data are available as concerns the association of different apoE alleles with two relatively rare forms of dementia, Pick's disease (PiD) and Huntington's disease (HD). In this study the frequency of the apoE4 allele was examined in 36 persons with histopathologically proven PiD and compared with that of the apoE genotype in 28 HD probands and 79 aged healthy controls. The E4 allele was overrepresented selectively in PiD (42%) as compared with the control population (7%). No such association was found for HD probands (9%). This finding lends further support to the hypothesis that the E4 genotype is not an Alzheimer's disease specific susceptibility factor, and that it could be present in diverse dementing disorders with tau protein related neuropathology, such as PiD.

Purification and characterisation of chicken brain hypoxanthine-guanine phosphoribosyltransferase.

Hypoxanthine-guanine phosphoribosyltransferase enzyme (EC 2.4.2.8) from chicken brain has been purified 10 000-fold to homogeneity. The molecular mass of the native enzyme is 85 kDa, with four subunits, each of 26 kDa, and exerts its maximum activity at pH 10.0. The Km values for hypoxanthine and guanine are 5.2 and 1.8 microM, respectively. The half-life of the enzyme is 30 min at 85 degrees C. Monoclonal antibodies were raised against the native purified enzyme and were used for purification of enzyme to homogeneity. The monoclonal antibody did not bind to the active centre of the enzyme.

Deletion patterns of dystrophin gene in Hungarian patients with Duchenne/Becker muscular dystrophies.

Deletion pattern analysis of the dystrophin gene was performed in 159 Hungarian patients with Duchenne/Becker muscular dystrophy. In 116 cases (73% of total patients), exon deletions were detected by PCR amplification. In 37 patients (31.9% of patients with a deletion) one exon was deleted, while five or more exons were missing in 40 children (34.4%). With respect to the proximal-distal distribution of the deletions, 90 children (77.6%) had deletions exclusively at the 3' end of the gene, 21 deletions (18.1%) affected only the 5' end, and in five patients (4.3%) large-scale deletions were detected, which affected both regions. Analysis of the breakpoint distribution pattern in the dystrophin gene showed that, similarly to that observed in several Western European populations, intron 44 was involved most frequently (n = 35, 15.1%) as a starting breakpoint. In the Hungarian population introns 50 and 52 were the second (n = 30, 12.9%) and third (n = 29, 12.5%) most frequently observed hot spots at the 3' end; these seem to be characteristic for the Hungarian patients. At the 5' end the breakpoint peak (n = 6, 2.58%) was in intron two. As it was proposed by previous national studies, our findings also suggest that certain intronic sequences, characteristic for a population, probably determine the development of a preferential breakpoint profile in this disease.

UVB irradiation-induced apoptosis increased in lymphocytes of Huntington's disease patients.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by CAG repeat expansion in the IT-15 gene coding for huntingtin. The mechanism of neuronal degeneration induced by the mutant huntingtin is not known. Apoptosis may play a role in it. Huntingtin is widely expressed in the cells, so abnormalities can be expected also in non-neural tissue. We examined the susceptibility of lymphocytes from HD patients, asymptomatic carriers and normal individuals to UVB irradiation-induced apoptosis. Lymphocytes from eight HD patients and two asymptomatic carriers showed increased apoptotic cell death compared to controls. Our results suggests that sensitivity of HD cells to induced apoptosis is not restricted to neurons.

Xeroderma pigmentosum variant or pigmented xerodermoid.

We describe herein a 29-year-old patient who was recognized as having a xeroderma pigmentosum variant or pigmented xerodermoid in the early adult life since sunlight sensitivity caused degenerative changes in the skin and cutaneous carcinomas. The patient had 11 skin tumours removed over an interval of two years, of which four proved to be squamous cell carcinoma, one basal cell carcinoma and six precancerous conditions. Then the patient was treated with isotretinoin at a dosage of 2 mg per kilogram of body weight per day for two years. During two years of treatment with isotretinoin a further three tumours were removed givind a histological result of basal cell carcinoma and Bowen's diseases. The patient tolerated well this low dosage retinoid treatment. Only 50 or so of these patients are described in the world literature.

Abnormal mutation frequencies in human repair-defective hybrid cell lines.

Two intraspecific human cell hybrids, HD2 and HD1A, produced from fusion between HeLa cells and xeroderma pigmentosum fibroblasts, express XPD-like rates of excision repair and hypersensitivity to UV-radiation. In the present paper we describe unusual patterns of UV-induced mutation in both cell lines. Though HD2 very closely resembles XPD both phenotypically and genetically, in UV-dose response it is hypomutable at the loci for ouabain and diphtheria toxin resistance. At equitoxic dose, however, it shows normal mutability, HD1A, by contrast, is hypermutable as a function either of UV dose or in terms of equitoxicity for these genes. HD1A's mutator phenotype is a dominant characteristic and is not associated with grossly abnormal DNA precursor pool imbalance. The possibility remains that DNA polymerase infidelity underlies its hypermutability.

Changes in alkylation damage removal during in vitro neuronal differentiation.

Mouse teratocarcinoma cell lines allow the analysis of very early commitment and differentiation events, that are likely to be similar to those operating in the early mouse embryo. We have previously characterised the excision repair capabilities of these cells after ultraviolet light irradiation and found that differentiation is accompanied by reduction of excision repair. In the present study we examine the operation of an other DNA repair pathway participating in the removal of alkylation damage. O6-alkylguanine-DNA alkyltransferase (ATase) activity was determined in undifferentiated and differentiated mouse P19 teratocarcinoma cell line. To obtain more information about regulation of ATase we transfected P19 cells with constructs harbouring a human ATase cDNA driven by a housekeeping promoter.

Molecular genetic studies in monogenic and polygenic human diseases.

The main goal of this study was to determine and characterise the types of mutations in two monogenic human disorders: cystic fibrosis (CF) and Duchenne/Becker muscular dystrophy (DMD, BMD) and the susceptibility allele frequency in a polygenic disease: type I insulin-dependent diabetes mellitus (IDDM). After analysing 220 chromosomes for mutations in the CF (Cystic Fibrosis Transmembrane Conductance Regulator = CFTR) gene, delta F508 mutation was most abundant (41%) and out of the non-delta F508 CF mutations 5% was identified as G542X, G551D, R553X, N1303K and W1282X. The CF haplotype analysis by using linked markers to the CFTR gene revealed that the CF "B" haplotype occurred in 66.7% of patients, and this haplotype was 57.2% in patients carrying the delta F508 mutation. Prenatal genetic diagnosis for CF was performed in 10 fetuses: 3 were affected, 6 were carriers, and 1 without any CF mutation. Fifty % of 66 patients with DMB/BMD muscular dystrophy had one or more exon deletions in the dystrophin gene. Eighty-five % of the deletions occurred at the 3' and 15% at the 5' end of the gene. Out of the three prenatal diagnosis in one case DMD was substantiated. Thirty-six % of 50 patients with IDDM possessed four, 44% three and 20% two susceptibility markers in the HLA-DQA1, -DQB1 region. The onset of the disease correlated with the number of susceptibility alleles.

[The DNA-chip, a new tool for medical genetics]. / Az orvosi genetikai diagnosztika új eszköze, a DNS-chip.

The DNA (chip) technology, emerged in the last two years, provides an incredible technical development in rapid and automatised performance of genetic identification. The principle of procedure is, that by series of photolitographic and chemical steps on solid-phase of a small surface relatively dense oligonucleotide arrays can be generated. The oligonucleotides produced by the computer-directed in-situ microfabrication may bind complementary fluorescent-labeled DNA fragments from the unknown sample. After scanning, the registered position of positive signals provide information on the identity of DNA fragments. By this novel approach not only DNA sequencing can be performed, but genetic errors of known genes, presence of infectious organisms and the typing of genetic markers (such as HLA) used for transplantation and forensic medicine can be determined. The DNA-chip technology is a revolutionary new milestone in genetic diagnose.

[A variant of xeroderma pigmentosum: two cases of pigmented xerodermoid]. / Xeroderma pigmentosum variáns: pigmentált xerodermoid két kóresete.

Two patients (sister and brother) of pigmented xerodermoid are presented: the character of clinical signs (phothosensitivity, poikilodermia, keratoses and keratomas, furthermore in the brother the squamous cell epithelioma of left thigh), according to them the case history (appearance of precancerous conditions and carcinoma in early adult life) made the disease suspicious to a variant of xeroderma pigmentosum. A DNA reparation test was also carried out, which confirmed the above clinical diagnosis in both patients.

[Gene deletion analysis in molecular diagnosis of Duchenne-Becker muscular dystrophy]. / Géndeletiók molekuláris diagnosztikai vizsgálata Duchenne- és Becker-izomdystrophiában.

Deletion analysis of the dystrophin gene (Xp21) was carried out by examinations of the most frequently deleted 18 exons (3., 4., 6., 8., 12., 13., 17., 19., 43., 44., 45., 47., 48., 49., 50., 51., 52. and 60. exon) and the muscle specific promoter in 42 Duchenne and Becker muscular dystrophy (DMD/BMD) affected patients with multiple polymerase chain reaction (PCR). 22 (52%) of 42 patients were found to have one or more exon deletions. 9% BMD patients (milder allelic form) were found in the deletion group versus 35% in the non deletion group. This method seems to be useful for prenatal genetic diagnosis in the family of deletion patients.