Tetrasomy 15q11-q13 Diagnosed by FISH in a Patient with Autistic Disorder

Karim Ouldim,Abdelaziz Sefiani,Philippe Jonveaux,Abdelhafid Natiq

doi:10.1155/2007/61538

Abstract

We report the case of a Moroccan boy with mental retardation, hyperactivity, epilepsy, developmental problems and behavioural disorders. Cytogenetic analysis showed the presence of a supernumerary marker chromosome. Molecular cytogenetics allowed us to determine the marker as an inverted duplication of chromosome 15. It is the first case of a Moroccan patient with tetrasomy 15q in which fluorescence in situ hybridization (FISH) enabled us to specify the diagnosis. Interestingly, this patient has an infantile autism with cytogenetic abnormalities on chromosomal region 15q11-q13 as reported in patients with Autistic Disorder.

Highlights

For more than 12 years, scientists have noticed that some individuals with autism have a chromosomal change involving specific part of chromosome 15 [1]
The supernumerary marker chromosome (SMC) was further characterized by fluorescence in situ hybridization (FISH) with a whole chromosome 15 painting probe, WCP15 (Vysis, Downers Grove, Ill, USA) and the Prader Willi/Angelman probe which contains three locus/region-specific probes: D15Z1 at the centromeric region, D15S10 at the 15q11-12 Prader-Willi Syndrome (PWS)/Angelman Syndrome (AS) critical region, and PML at 15q22 (Vysis, Downers Grove, Ill, USA)
To further characterize this marker, FISH analysis was carried out using the Vysis Prader Willi/Angelman region probes

Summary

Introduction

For more than 12 years, scientists have noticed that some individuals with autism have a chromosomal change involving specific part of chromosome 15 [1]. Trisomy or tetrasomy of the 15q11-q13 region has been reported in some autistic patients with varying degrees of mental retardation [2,3,4]. This report describes a male patient with autistic disorder, and a supernumerary marker chromosome (SMC). Molecular cytogenetic investigation using FISH method allowed us to characterize the marker as an inv dup(15) including the Prader Willi/Angelman locus. This patient has a tetrasomy for the 15q11-q13 chromosomal region. This observation reinforces the hypothesis that additional copies of proximal chromosome 15 segment may be causally related to autism

Methods

Results

Conclusion