Trisomy and tetrasomy 15q11-q13 diagnosed by molecular cytogenetic analysis in two patients with mental retardation

Inesse Ben Abdallah Bouhjar; Abir Gmidène; Najla Soyah; Hannachi Hanene; Soumaya Mougou; Hatem Elghezal; Ali Saad

doi:10.3233/PGE-2012-012

Journal of Pediatric Genetics, Table of Contents

J Pediatr Genet 2012; 01(01): 063-068
DOI: 10.3233/PGE-2012-012

Georg Thieme Verlag KG Stuttgart – New York

Trisomy and tetrasomy 15q11-q13 diagnosed by molecular cytogenetic analysis in two patients with mental retardation

Inesse Ben Abdallah Bouhjar

^aDepartment of Cytogenetic and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia

^bCommon Service Units for Research in Genetics, Faculty of Medicine of Sousse, Sousse, Tunisia

,

Abir Gmidène

^aDepartment of Cytogenetic and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia

^bCommon Service Units for Research in Genetics, Faculty of Medicine of Sousse, Sousse, Tunisia

,

Najla Soyah

^cDepartment of Pediatrics, Farhat Hached University Teaching Hospital, Sousse, Tunisia

,

Hannachi Hanene

^aDepartment of Cytogenetic and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia

^bCommon Service Units for Research in Genetics, Faculty of Medicine of Sousse, Sousse, Tunisia

,

Soumaya Mougou

^aDepartment of Cytogenetic and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia

^bCommon Service Units for Research in Genetics, Faculty of Medicine of Sousse, Sousse, Tunisia

,

Hatem Elghezal

^aDepartment of Cytogenetic and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia

^bCommon Service Units for Research in Genetics, Faculty of Medicine of Sousse, Sousse, Tunisia

,

Ali Saad

^aDepartment of Cytogenetic and Reproductive Biology, Farhat Hached University Teaching Hospital, Sousse, Tunisia

^bCommon Service Units for Research in Genetics, Faculty of Medicine of Sousse, Sousse, Tunisia

› Author Affiliations
Subject Editor:

Abstract

PDF Download

Abstract

In this study, we report two patients with the supernumerary marker chromosome (15)s. The first case is an 8.5-year-old girl with an inv dup (15) syndrome, mental retardation and dysmorphic features. The second case is a 13-year-old boy with a ring chromosome 15, who was referred to the Laboratory of Cytogenetic and Biology of Reproduction in Sousse, Tunisia for mental retardation, epilepsy, speech delay, hypotonia and other mild dysmorphic features. R banding showed the presence of a marker chromosome in both cases. Molecular cytogenetic investigation using fluorescence in situ hybridization method allowed us to characterize the markers including the Prader-Willi syndrome locus that contains the small nuclear ribonucleoprotein polypeptide N (SNRPN) gene. Tetrasomy and trisomy for the 15q11-q13 chromosomal region were found in the first and the second patient, respectively. This observation reinforces the hypothesis that additional copies of proximal chromosome 15q11 segment may be causally related to mental retardation and dysmorphic features.

Keywords

Mental retardation - inv dup (15) syndrome - ring chromosome 15 syndrome - FISH

PDF (893 kb)