Génétique humaine et Embryologie

Ring Chromosome and Clinical Findings: Reports Cases of 4 Different Chromosomes in Beninese Population

Abstract

Azonbakin S, Adjagba M, Gangbo F, Laleye A and Maroufou Alao J

Ring chromosome is a disorder in which one or both ends of chromosome are lost and joined, so they could show a ring-shaped structure. Patients with ring chromosome could therefore present with features of deletion of long or short arms of the chromosome syndromes or a combination of both. Phenotypic of these individuals depends on the size of the ring chromosome, amount of genetic material lost in breakage, the stability of the ring chromosome and the presence of secondary chromosomal aberrations including the varying degrees of mosaicism. Ring chromosomes accounts for a very low percentage of structural chromosomal abnormalities but could lead to a major clinical concern and complicated genetic counseling. Practitioner awareness must be permanently raised up to help in managing with efficacy patient with ring condition. We report here 4 cases of ring on chromosome 4, 9, 15 and X. We described their clinical finding and draw attention on common key signs that were present in the reported cases and also discussed recurrence risk.