Exclusion of chromosomal abnormalities and microdeletions 22q11 and 10p13 in algerian patients with isolated conotruncal malformation

Abstract

The chromosomal abnormalities of number and structure or the 22q11.2 and 10p13-14 microdeletions are considered the main causes of congenital heart disease. In our best knowledge, cytogenetics studies on congenital heart diseases (CHD) have not been performed in Algeria. In this study, we will screen for chromosomal abnormalities and microdeletions of 22q11.2 and 10p13 in a cohort of Algerian patients. G-banded by trypsin Giemsa (GTG) and Fluorescent In Situ Hybridization (FISH) techniques have been performed to screen for chromosomal abnormalities and a critical regions 22q11.2 and 10p13-14 respectively in seventy patients with non syndromic congenital heart. GTG technique visualized no chromosomal abnormalities of number and structure in our patients. Moreover, FISH visualizing critical regions 22q11.2 and 10p13-14 respectively did not detect any microdeletion in the chromosomes 10 and 22 respectively of our patients. Our study could suggest that congenital heart defects observed in Algerian patients are not due to chromosomal abnormalities of number and structure nor the 22q11.2 and 10p13-14 microdeletions. For the fist time, we report here cytogenetics analysis of chromosomal abnormalities and the 22q11.2 and 10p13-14 microdeletions in Algerian patients with congenital heart disease. Genetic testing for screening for deletion 22q11.2 and 10p13-14 is not indicated in all patients with isolated conotruncal defects. In addition, conotruncal heart diseases have a multifactorial background like consanguinity and recessive mutations in some genes involved in cardiac morphogenesis. A genetic study to screen for the role of consanguineous marriages and some genes linked to CHD in Algerian population is on going. This study will focus also on health education for the families at risk about the importance of pre-marital genetic counseling.