Peter Steinbach

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The CGG repeat in the 5' untranslated region of the fragile X mental retardation 1 gene (FMR1) exhibits remarkable instability upon transmission from mothers with premutation alleles. A collaboration of 13 laboratories in eight countries was established to examine four issues concerning FMR1 CGG-repeat instability among females with premutation(More)
OBJECTIVE Myotonic dystrophy type 1 and 2 (DM1/DM2) are multisystemic diseases with common cognitive deficits beside the cardinal muscular symptoms. We performed a comprehensive analysis of cerebral abnormalities to compare the neuropsychological defects with findings in different imaging methods in the same cohort of patients. METHODS Neuropsychological(More)
Eleven folic acid sensitive fragile sites (3p14, 7p13, 7q31.1, 7q32, 9q32, 11p13, 14q23, 15q22, 16q23, Xp22.2, Xq22) were detected in one individual, eight of them previously unknown. These sites seem to bear each its specific sensitivity to folic acid deficiency. Six of the sites were observed simultaneously on both homologous chromosomes in at least one(More)
We report on further cases of high functioning fragile X males showing decreased expression of FMR1 protein, absence of detectable methylation at the EagI site in the FMR1 gene promoter, and highly unusual patterns of fragile X mutations defined as smear of expansions extending from premutation to full mutation range. Very diffuse and therefore not easily(More)
Fragile sites on murine chromosomes were induced by the antimetabolites methotrexate (MTX), fluorodeoxyuridine (FdU), and aphidicolin (APD). To facilitate chromosome identification the analysis was performed on chromosomes of a CD/CD mouse that possesses nine pairs of Robertsonian translocation chromosomes of known arm composition. The pattern of induced(More)
We demonstrate here that somatic variation of CGG repeat length is based on a mosaic of cells with different but stable FMR-1 alleles and does not reflect permanent mitotic instability. The length of a particular allele in an individual cell was maintained in progeny cells establishing a clone. The mutation patterns of multiple repeats in the DNA of fetal(More)
We have analysed the mitotic behaviour of expanded CTG repeats in somatic tissues and cultured somatic cells from myotonic dystrophy (DM) fetuses using indirect and direct methods. Heterogeneity of expansions between fetal tissues was demonstrated in a 16 week old fetus whereas there was no evidence for such a somatic heterogeneity in a 13 week old fetus.(More)
To elucidate the function of the FMR1 gene, we applied RNA in situ hybridization to cryosections of mice from different developmental stages. The murine Fmr-1 was found transcribed in a ubiquitous manner with an expression pattern similar to glyceraldehyd phosphate dehydrogenase, Gapdh, which was used as a control gene. A significant difference in the Fmr-1(More)
Myotonic dystrophy (DM1) and proximal myotonic myopathy (PROMM or DM2) are two distinct muscular disorders with multisystemic involvement. Both have previously been reported to be associated with cognitive impairment and white matter lesions detected by cerebral magnetic resonance imaging (MRI). In this study, the extent of brain atrophy was investigated in(More)
Modern biotechnology has developed powerful tools for genetic engineering and flower colours are an excellent object to study possibilities and limitations of engineering strategies. Osteospermum hybrida became a popular ornamental plant within the last 20 years. Many cultivars display rose to lilac flower colours mainly based on delphinidin-derived(More)