Abstract
INTRODUCTION: The 22q11.2 deletion syndrome (22q11DS) is an autosomal dominant genetic syndrome, frequently due to a microdeletion located on chromosome 22, presenting a wide variety of clinical manifestations. Cytogenetic methods, such as fluorescence in situ hybridization (FISH), and molecular biology techniques, such as multiplex ligation-dependent probe amplification (MLPA), are used to identify chromosomal deletions specific to the 22q11.2 region. AIM: This study aimed to describe the first series of pediatric patients in Morocco, selected for their strong suspicion of DiGeorge syndrome. METHODS: As part of a collaboration between the University Hospital Center Hassan II in Fez and the University Hospital Center Abderrahim El Harouchi Ibn Rochd in Casablanca, Morocco, a prospective study was carried out from January 2021 to January 2024 on 30 patients screened for DiGeorge syndrome (DGS). The children included had at least two major signs of DGS. Diagnostic confirmation of 22q11DS was obtained by FISH analysis for all patients. In addition, MLPA analysis was performed on five patients among those confirmed by FISH. The MLPA process included DNA extraction, PCR amplification and capillary electrophoresis, with results analyzed using GeneMapper and Coffalyser software. RESULTS: Of the 30 patients selected, 22 were confirmed as having a 22q11DS. Among these, 19 had congenital heart disease and 17 had hypocalcemia, which was often associated with hypoparathyroidism. Facial dysmorphia was almost constant, and thymic abnormalities were observed in half the patients. Recurrent infections, hematological disorders and immune abnormalities were also common, underlining the clinical complexity of the syndrome. CONCLUSION: Advances in molecular cytogenetics have enabled precise detection of microdeletions associated with 22q11DS, highlighting its global importance, but also revealing regional diagnostic challenges. Larger cohort studies are needed to strengthen the validity of results and improve clinical management approaches.