Growth advantage of CD34+ cells in trisomy 8 high-risk myelodysplastic syndrome despite enhanced apoptotic signals

This study examined haematopoietic stem cells of 19 high-risk cases of myelodysplastic syndrome [MDS] for apoptotic and anti-apoptotic signals and cellular proliferation and correlated these with clinical and cytogenetic subtypes, particularly trisomy 8. The aim was to identify cellular and cytogenetic markers of prognostic relevance to survival of high-risk MDS cases. High-risk MDS cases had a significantly higher percentage of apoptotic CD34+ cells and anti-apoptotic survivin+ cells than controls, particularly for trisomy 8 cases. Trisomy 8+ cells showed a significant positive correlation with apoptotic CD34+ cells and capacity for colony formation. The latter was significantly lower in trisomy-8-negative cases than normal controls, while that of trisomy 8 cases was comparable to controls. Our results suggest that although trisomy 8 cells are in a pro-apoptotic state, they are checked by the enhanced expression of anti-apoptotic signals which provide them with their proliferative advantage

Use of FISH technique in the diagnosis of chromosomal syndromes

Major chromosome abnormalities are present in 0.65% of all neonates. Fluorescent in situ hybridization [FISH] is useful in diagnosing microdeletion syndromes that would otherwise be difficult to diagnose using standard cytogenetics. In this study, we used FISH analysis in the laboratory diagnosis of 4 patients with Prader-Willi Syndrome [del[15][q11.2q12]], 4 patients with DiGeorge syndrome [del[22][q11.2q11.23]] and 4 patients with Williams syndrome [del[7][q11.23q11.23]]. High-resolution chromosome analysis in all these patients was either normal or inconclusive but all the syndromes were confirmed using FISH. We recommend cytogenetic analysis should always be supplemented with FISH to diagnose all cases suspected of a microdeletion syndrome

A diagnostic clinical genetic study of craniofacial dysmorphism

A diagnostic evaluation of craniofacial anomalies, either isolated or as part of a genetic syndrome was conducted on 25 patients [8 females, 17 males], age range 2 months to 47 years. Complete genetic examination, pedigree analysis, anthropometric measurements and radiological studies were carried out. Cytogenetic studies included fluorescence in situ hybridization [FISH] when indicated. In all, 15 patients had chromosomal abnormalities. Five patients had unbalanced chromosome rearrangements and six had chromosome markers. Three patients were FISH-positive for William syndrome and one was positive for Prader-Willi syndrome. Ten patients had monogenic disorders. Five were diagnosed as craniosynostosis syndromes. We conclude that minor features are useful for making a diagnosis of congenital anomalies