engleski

Interstitial deletion of the short arm of chromosome 8 in a boy with mild phenotype and normal development

We describe a 3-year-old boy who presented with microcephaly and mild dysmorphic facial features. Cytogenetic studies on high-resolution G and R banding showed a large de novo 8p deletion. The designated karyotype was 46, XY, del(8)(p21-ter). His psychomotor and somatic development were within normal range, and detailed clinical examination did not reveal either congenital heart malformation or characteristic hyperactive and aggressive behaviour usually associated with 8p deletion phenotype. Therefore cytogenetic reassessment of breakpoint positions was performed by FISH analysis using a subtelomere probe for 8p and YAC-s covering chromosome bands 8p22-8p23.1. The revised breakpoints showed proximal interstitial deletion not involving the commonly deleted 8p23.1 region. This supports the evidence that the critical region for heart defect and behavioural problems in 8p deletion syndrome is at the band 8p23 with the distal breakpoint between markers D8S1825 and D8S1706 and with the proximal breakpoint at D8S1759 and D8S1695 (1). When the deviation from the expected clinical spectrum is observed, further FISH and DNA analyses are indicated in order to refine genotype-phenotype correlation and to characterise with more precision critical segment region.

chromosome 8p deletion

nije evidentirano