Nijmegen breakage syndrome (NBS) is a chromosomal instability disorder, clinically characterised by microcephaly, immunodeficiency, radiosensitivity and a very high predisposition to lymphoid malignancy. Recently, it was demonstrated that mutations in the NBS1 gene are responsible for NBS. Most of the NBS patients known so far are of Slav origin and carry a major founder mutation 657del5 in exon 6 of the NBS1 gene. In this study we estimated the prevalence of the 657del5 mutation in the Czech Republic, Poland and the Ukraine. We found an unexpectedly high carrier frequency of the 657del5 mutation (1/177) in the three Slav populations, a factor that may contribute to cancer frequency in those countries. In addition, we show that NBS patients are often diagnosed late and therefore receive inappropriate therapy. European Journal of Human Genetics (2000) 8, 900-902.

No abstract

Gastroesophageal disease (GERD) is the one of most spread diseases that injures an esophagus. Taking into account the large number of factors that can cause GERD development already in child age, including genetic predisposition, it is necessary to analyze each of them in detail. Aim of this work was to analyze a frequency and possible association type of р. Leu72Met mutation of GHRL gene in children with gastroesophageal reflux disease. The analysis of clinical parameters and course of disease in the group of 100 schoolchildren with GERD was carried out. The molecular-genetic study of c.214C>A locus of GHRL gene by CPR method (rs696217) was carried out in patients with GERD and 40 healthy children from the control group. In 82% of children with GERD was revealed a GHRL 214СС (Leu/Leu) homozygous genotype, at 58% among children from the control group. GHRL 214СА (Leu/ Met) genotype was registered three times more seldom in children of the studied group comparing with ones from the control group: 15,0% and 42,5%, respectively. It was established, that GHRL 214CС genotype presence conditions the increase of GERD development risk in 3,4 times. On the contrary, GHRL 214CА genotype manifests a reliable protective effect that is essentially decreased GERD development risk in a child at such genotype – 0,24 comparing with a conventional unit. There was established alleles and genotypes distribution of c.214C>A (р.Leu72Met) locus of GHRL gene in children with GERD. GHRL 214CС genotype is associated with threefold increase of GERD risk development. Gender differences as to GERD development risk at different genotypes of ghrelin gene were established. At GHRL 214СС (Leu/Leu) genotype the relative GERD risk for boys increased in more than 6 times. There were not established any differences in alleles and genotypes distribution depending on erosive or surface inflammatory changes of a gastrointestinal tract mucosa.