Belkady Boutaina, Elkhattabi Lamiae, Elkarhat Zouhair, Zarouf Latifa, Razoki Lunda, Aboulfaraj Jamila, Nassereddine Sanaa, Cadi Rachida, Rouba Hassan, Barakat Abdelhamid
Laboratory of Genomics and Human Genetics, Institut Pasteur du Maroc, Casablanca, Morocco.
Laboratory of Molecular Genetics and Biotechnology, Faculty of Science Ain Chock, Casablanca, Morocco.
Hum Hered. 2018;83(5):274-282. doi: 10.1159/000499710. Epub 2019 May 7.
Intellectual disability (ID) has been defined as a considerably reduced ability to understand new or complex information and to learn new skills. It is associated with life-long intellectual and adaptive functioning impairments that have a profound impact on individuals, families, and society. It affects about 3% of the general population. ID often comes out with other mental conditions like attention deficit, hyperactivity, and autism spectrum disorders (ASD), and it can be part of a malformation syndrome that affects other organs. It may be syndromic (S-ID) or non-syndromic (NS-ID).
The aims of this study were to identify the profile of intellectually disable patients being referred for cytogenetic analysis in Morocco, to determine the prevalence of chromosomal abnormalities in a Moroccan group, and to compare the results with those of analogous studies from other countries.
We included data from Moroccan patients with NS-ID and others with S-ID (mostly Down syndrome cases) who have been referred between 1996 and 2016. 1,626 patients were involved in this study, 1,200 were referred with a clinical diagnosis of Down syndrome, 37 were clinically diagnosed for ASD with ID, and 389 were suspected of NS-ID.
We identified 1,200 cases of Down syndrome. In 1,096 analyses (91.3%), a cytogenetic variant of trisomy 21 was identified: standard trisomy 21 in 1,037 cases (94.6%), a translocation in 34 cases (3.10%), and mosaicism in 25 cases (2.3%). The cytogenetic analysis among ASD with ID cases did not reveal any specific chromosomal abnormalities. The present study also shows that chromosomal abnormalities were present in 6.43% of the patients with NS-ID (25 abnormal karyotypes out of 389 NS-ID cases). Autosomal structural abnormalities were the largest proportion of chromosomal aberrations.
The high rate of chromosomal abnormalities found in the Moroccan patients studied demonstrates the capital importance of cytogenetic evaluation in patients who show ID or any clinical development abnormality.
智力残疾（ID）被定义为理解新的或复杂信息以及学习新技能的能力显著降低。它与终身的智力和适应性功能障碍相关，对个人、家庭和社会产生深远影响。它影响着约3%的普通人群。ID常与其他精神状况同时出现，如注意力缺陷、多动和自闭症谱系障碍（ASD），并且它可能是影响其他器官的畸形综合征的一部分。它可能是综合征性的（S-ID）或非综合征性的（NS-ID）。
本研究的目的是确定在摩洛哥被转诊进行细胞遗传学分析的智力残疾患者的概况，确定摩洛哥人群中染色体异常的患病率，并将结果与其他国家的类似研究结果进行比较。
我们纳入了1996年至2016年间被转诊的摩洛哥非综合征性智力残疾患者以及其他综合征性智力残疾患者（主要是唐氏综合征病例）的数据。1626名患者参与了本研究，其中1200名因临床诊断为唐氏综合征而被转诊，37名临床诊断为患有ASD且伴有智力残疾，389名疑似非综合征性智力残疾。
我们鉴定出1200例唐氏综合征病例。在1096次分析（91.3%）中，鉴定出21三体的细胞遗传学变异：1037例（94.6%）为标准21三体，34例（3.10%）为易位，25例（2.3%）为嵌合体。伴有智力残疾的ASD病例的细胞遗传学分析未发现任何特定的染色体异常。本研究还表明，389例非综合征性智力残疾患者中有6.43%（25例异常核型）存在染色体异常。常染色体结构异常在染色体畸变中占最大比例。
在我们研究的摩洛哥患者中发现的高染色体异常率表明，细胞遗传学评估对于表现出智力残疾或任何临床发育异常的患者至关重要。
