Conventional and molecular cytogenetic characterization of a Moroccan patient with WAGR syndrome

Abstract

WAGR syndrome is a rare genetic disorder characterized by a de novo deletion of 11p13 and is usually clinically associated with Wilms’ tumor, aniridia, genitourinary anomalies, and mental retardation (W-A-G-R). Although the genotypic defects in WAGR syndrome have been well established. The congenital aniridia is caused, in nearly 90% of cases by mutations in the gene PAX6. In the face of congenital aniridia, it is imperative to specify whether it falls within the scope of a WAGR syndrome or if it is an isolated congenital aniridia or inherited by performing karyotype, FISH (Fluorescence In Situ Hybridization) or a CGH array for genetic counseling. We report here a case of genetic testing for newborn with aniridia, to detect 11p13 rearrangements, using karyotyping and CGH array to complete picture of the chromosomal deletions and breakpoints in aniridia. Results show either a loss of 3811.196 kb on chromosome 11 delimited by the bands p14.1 and p13 with formula or a loss of a 1867.287 kb on chromosome 18 fragment delimited by q21.33 and q22.1 bands, that has not been detected by karyotype analysis. Cytogenetics screening is a good strategy for the genetic diagnosis of aniridia and associated syndromes, allowing for a better identification of breakpoints. Our results underline the clinical importance of performing exhaustive and accurate analysis of chromosomal rearrangements for patients with aniridia, especially newborns to improve survival and quality of life for affected individuals.