Screening of the duplication 24 pb of ARX gene in Moroccan patients with X-linked Intellectual Disability.

OBJECTIVE: Intellectual Disability (ID) represents a neuropsychiatric disorder, which its etiopathogenesis remains insufficiently understood. Mutations in the Aristaless Related Homeobox gene (ARX) have been identified to cause syndromic and nonsyndromic (NS-ID). The most recurrent mutation of this gene is a duplication of 24pb, c.428-451dup. Epidemiological and genetic studies about ID in the Moroccan population remain very scarce, and none study is carried out on the ARX gene. This work aimed to study c.428-451dup (24 bp) mutation in the exon 2 of the ARX gene in 118 males' Moroccan patients with milder NS-ID to evaluate if the gene screening is a good tool for identifying NS-ID. RESULTS: Our mutational analysis did not show any dup(24pb) in our patients. This is because based on findings from previous studies that found ARX mutations in 70% of families with NS-ID, and in most cases, 1.5-6.1% of individuals with NS-ID have this duplication. Since 1/118 = 0.0084 (0.84%) is not much different from 1.5%, then it is reasonable that this could a sample size artifact. A complete screening of the entire ARX gene, including the five exons, should be fulfilled. Further investigations are required to confirm these results.

Intellectual Disability in Morocco: A Pilot Study.

Objective: Intellectual disability (ID) is a heterogeneous group of disorders characterized by a congenital limitation in intellectual functioning and adaptive behaviour. Our present work aimed to describe the demographic and clinical characteristics in a series of Moroccan individuals with ID living in Fez city and its regions. Design: It was a prospective and descriptive exploratory monocentric study carried out between October 2014 and July 2019. We selected 186 patients diagnosed with ID at three different centers in Fez city. The data were processed and analyzed using the IBM SPSS version 24. Results: Our data revealed a high frequency of male patients with ID (67.2% in male patients vs. 32.8% in female patients). The male-to-female ratio was 2.04. The mean age of our patients was 15.52 ±6.59 years (mean±SD), ranging between 2 and 36 years. The mean age of fathers and mothers at the birth of their child with ID was 36 and 28 years, respectively. Several abnormal behaviors were observed: 23.1 percent delayed language learning, 17.7 percent anxiety, 12.9 percent aggressiveness, 19.18 percent concentration problems, and 5.4 percent hyperactivity. Epileptic seizures were the most common mental health disorder (21.72%) observed in our patients. Approximately 25 percent of patients with epilepsy took antiepileptic and/or neuroleptics to prevent the occurrence of seizures. Conclusion: A significant correlation was observed between ID associated to genetic causes and the increase of consanguinity rate.