First report on chromosomal abnormalities in Eastern Morocco: Identification of a new case of a de novo partial trisomy 13q using single-nucleotide polymorphism array
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引用次数: 0
Abstract
Background
Chromosomal abnormalities are the main cause of birth defects, intellectual disability, and miscarriages. They contribute to significant human morbidity and infant mortality. Here we report for the first time the chromosomal abnormalities encountered in the population of Eastern Morocco. Furthermore, we describe a new case of a de novo partial trisomy 13q combined with a terminal deletion in an 11-day-old girl.
Methods
From November 2015 to March 2022, 195 patients from the BRO Biobank who were clinically suspected of having chromosomal abnormalities were referred to the cytogenetics laboratory of the Genetics Unit of the Faculty of Medicine and Pharmacy of Oujda for cytogenetic study. Karyotyping analysis was performed on peripheral blood samples using standard R banding techniques. To identify single-nucleotide polymorphism (SNP) and copy number variants (CNVs), Illumina SNP array was used.
Results
Among 195 studied cases, 32 (16.4 %) had abnormal karyotypes, of which 12 cases had numerical aberrations while 20 cases had structural aberrations. The most common numerical aberrations were Turner syndrome and Down syndrome followed by Edward, Patau, and Klinefelter syndromes. For structural aberrations, translocations were the most common, followed by derivative chromosomes, inversions, deletions, and an addition on chromosome 13 identified in an 11-day-old girl. To further characterize this addition, SNP array was carried out and revealed a 58.8-Mb duplication in region 13q14.3q34 associated with a 1-Mb deletion in region 13q34. Follow-up parental chromosomes analysis showed normal karyotypes for the parents, confirming that this partial trisomy 13q was de novo. Comparison of the phenotype associated with this novel duplication on chromosome 13q with those previously reported confirmed the considerable variability in the phenotype of the patients with partial trisomy 13q.
Conclusion
This study provided the first report on chromosomal abnormalities in Eastern Morocco and it enriched the phenotype spectrum of partial trisomy 13q and further confirmed the genotype–phenotype correlations. Furthermore, these findings justify the need to set up microarray comparative genomic hybridization techniques in Morocco for better genetic diagnosis.
期刊介绍:
Archives de Pédiatrie publishes in English original Research papers, Review articles, Short communications, Practice guidelines, Editorials and Letters in all fields relevant to pediatrics.
Eight issues of Archives de Pédiatrie are released annually, as well as supplementary and special editions to complete these regular issues.
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Archives de Pédiatrie is the official publication of the French Society of Pediatrics.