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Original Research

The 22q11.2 Deletion Syndrome in Congenital Heart Defects: Prevalence of Microdeletion Syndrome in Cameroon

Authors
  • Ambroise Wonkam
  • Ricardo Toko
  • David Chelo
  • Cedrik Tekendo-Ngongang
  • Samuel Kingue
  • Sophie Dahoun

Abstract

Background: The 22q11.2 deletion syndrome is amongst the most common microdeletion syndrome in humans. Its prevalence remains unknown in sub-Saharan Africa, and its clinical features are underreported for people of African descent.

Objective: We have investigated the prevalence of the 22q11.2 deletion syndrome in patients with congenital heart defects in Cameroon.

Methods: A total of 70 of 100 cases of congenital cardiac malformation with echocardiographic evidence were examined prospectively and tested for the 22q11.2 deletion, using multiplex ligation-dependent probe amplification and fluorescence in situ hybridization.

Results: Two of 70 patients (2.8%) were found to have 22q11.2 deletion. Both cases had conotruncal heart defects and exhibited extracardiac features of the 22q11.2 deletion syndrome that were either classical (e.g., puffy upper eyelids, bulbous tip of the nose) or less identifiable (telecanthus, hooding of eyelids and prominent nasal bridge).

Conclusions: The report shows that the prevalence of the 22q11.2 deletion syndrome in patients with heart malformations in Cameroon (2.8%) is similar to that of various world populations. The clinical phenotypes will contribute to the Global Atlas for dysmorphology. “Omics” technologies offer much promise in genetic/genomic screening of severe global health problems.

Highlights

  • The 22q11.2 deletion syndrome is the most frequent microdeletion syndrome, among the most common genetic conditions in humans, and its prevalence is unknown in sub-Saharan Africa.
  • Using multiplex ligation-dependent probe amplification (MLPA), and fluorescence in situ hybridization (FISH), we report that 2 of 70 patients (2.8%), Cameroonian children with congenital cardiac malformations, were found to have 22q11.2 deletion.
  • Awareness should be raised by health practitioners for suspicion and screening of the 22q11.2 deletion syndrome, in patients with conotruncal malformations with or without craniofacial dysmorphism.
  • The clinical features of the 2 cases presented here will contribute to the Global Atlas for dysmorphology, as very few studies are reported on dysmorphic signs in 22q11.2 deletion syndrome in individuals of African descent.
  • OMICS technologies offer much promise in genetic/genomic screening of severe global health problems.
Published on Jun 1, 2017
Peer Reviewed