Triple-A Syndrome in Morocco: Founder Effect, Age Estimation of the AAAS c.1331+1G>A Variant, and Implications for Genetic Diagnosis.

Introduction: Triple-A syndrome (Triple-A) is an autosomal recessive disorder characterized by alacrimia, achalasia, and adrenal insufficiency. Several variants on the AAAS gene have been described, and some variants are clustered in particular geographical areas, such as the c.1331+1G>A variant which is very frequent in North Africa. Here, we describe the genetic features of Triple-A in a series of unrelated families from Morocco. Methods: Screening for the AAAS c.1331+1G>A variant was performed by direct sequencing or by PCR-RFLP. Haplotype analysis using Single Tandem Repeat (STR) markers flanking AAAS gene was performed in order to evaluate the founder effect and estimate the age of the c.1331+1G>A variant. Results: Seven unrelated families with ten individuals clinically diagnosed with Triple-A were evaluated for sequence variations in the AAAS gene. The median age at diagnosis was 3 years, with a range between 2 and 11 years. Molecular analysis revealed that all patients were homozygous for the c.1331+1G>A variant. This variant was not found in 200 healthy controls, indicating that carriers are very rare in the general Moroccan population. Subsequently, STR marker analysis revealed a founder effect and that the most recent common ancestor of Triple-A patients in Morocco would have lived 125 years ago. Conclusion: This is the largest series of Triple-A in Morocco. The same AAAS c.1331+1G>A variant was found in all patients, suggesting a founder effect in Morocco which was subsequently confirmed by microsatellite marker analysis. Therefore, this variant should be systematically investigated to diagnose Triple-A in Morocco.

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.

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.

A novel variant in BMPR1B causes acromesomelic dysplasia Grebe type in a consanguineous Moroccan family: Expanding the phenotypic and mutational spectrum of acromesomelic dysplasias.

Acromesomelic dysplasia Grebe type (AMD Grebe type) is an autosomal recessive trait characterized by short stature, shortened limbs and malformations of the hands and feet. It is caused by variants in the growth differentiation factor 5 (GDF5) or, in rare cases, its receptor, the bone morphogenetic protein receptor-1B (BMPR1B). Here, we report a novel homozygous BMPR1B variant causing AMD Grebe type in a consanguineous Moroccan family with two affected sibs from BRO Biobank. Remarkably, the affected individuals showed additional features including bilateral simian creases, lumbar hyperlordosis, as well as lower limb length inequality and dislocated hips in one of them, which were never reported previously for AMD Grebe type patients. The identified novel BMPR1B variant (c.1201C>T, p.R401*) is predicted to result in loss of function of the BMPR1B protein either by nonsense-mediated mRNA decay or production of a truncated BMPR1B protein. Thus, these findings expand the phenotypic and mutational spectrum of AMD, and may improve the diagnosis of AMD and enable appropriate genetic counselling to be offered to patients.

Molecular heterogeneity of ß-thalassemia variants in the Eastern region of Morocco.

BACKGROUND: ß-thalassemia syndromes are the most common hereditary blood disorders in the world and are recognized as a major health problem in Morocco. They are characterized by the reduction or the absence of ß-globin chain synthesis. The severity of the disease depends on the nature of the variants affecting the ß-globin gene (HBB), and each ethnic group has its own mutation spectrum. Hereby, we present, for the first time, the molecular profile of ß-thalassemia in the Eastern region of Morocco. METHODS: This study concerns 39 cases from 33 families who were enrolled in the BRO Biobank. Nineteen were diagnosed with ß-thalassemia major and 20 with ß-thalassemia minor. To detect mutations of the ß-globin gene, we have used RFLP-PCR and Sanger sequencing. RESULTS: Nine known ß-thalassemia variants have been identified. Among these, we reported, for the first time in the Moroccan population, the Czechoslovakian variant C38/39(-C) at homozygous state. The C39(C > T) was the most frequent variant (72.54%), followed by FSC5(-CT) (5.88%), FSC6(-A), IVS-1-110(G > A), -29(A > G), C38/39(-C) (3.92% each), and finally by IVS-I-1(G > A), IVS-II-1(G > A), and -56(G > C) (1.96%). Of particular interest this mutational spectrum of ß-thalassemia is very different from that found in previous studies in Morocco or in other North African countries. CONCLUSION: This study is the first contribution to the description of the molecular profile of ß-thalassemia in the Eastern region of Morocco. It shows the high molecular heterogeneity of ß-thalassemia in our country. Therefore, these results can be valuable for the implementation of carrier screening, genetic counseling, and prenatal diagnosis programs.

Morocco's First Biobank: Establishment, Ethical Issues, Biomedical Research Opportunities, and Challenges.

BACKGROUND: Biobanks are highly organized infrastructures that allow the storage of human biological specimens associated with donors' personal and clinical data. These infrastructures play a key role in the development of translational medical research. In this context, we launched, in November 2015, the first biobank in Morocco (BRO Biobank) in order to promote biomedical research and provide opportunities to include Moroccan and North African ethnic groups in international biomedical studies. Here, we present the setup and the sample characteristics of BRO Biobank. METHODS: Patients were recruited at several departments of two major health-care centers in the city of Oujda. Healthy donors were enrolled during blood donation campaigns all over Eastern Morocco. From each participant, personal, clinical, and biomedical data were collected, and several biospecimens were stored. Standard operating procedures have been established in accordance with international guidelines on human biobanks. RESULTS: Between November 2015 and July 2020, 2446 participants were recruited into the BRO Biobank, of whom 2013 were healthy donors, and 433 were patients. For healthy donors, the median age was 35 years with a range between 18 and 65 years and the consanguinity rate was 28.96%. For patients, the median age was 11 years with a range between 1 day and 83 years. Among these patients, 55% had rare diseases (hemoglobinopathies, intellectual disabilities, disorders of sex differentiation, myopathies, etc.), 13% had lung cancer, 4% suffered from hematological neoplasms, 3% were from the kidney transplantation project, and 25% had unknown diagnoses. The BRO Biobank has collected 5092 biospecimens, including blood, white blood cells, plasma, serum, urine, frozen tissue, FFPE tissue, and nucleic acids. A sample quality control has been implemented and suggested that samples of the BRO Biobank are of high quality and therefore suitable for high-throughput nucleic acid analysis. CONCLUSIONS: The BRO Biobank is the largest sample collection in Morocco, and it is ready to provide samples to national and international research projects. Therefore, the BRO Biobank is a valuable resource for advancing translational medical research.

Patients' Knowledge and Attitude Toward Biobanks in Eastern Morocco.

Background: To integrate biobanks into the Moroccan health system and to promote biobanks-based research projects, it is necessary to explore the knowledge of patients, their attitudes toward biobanks, and the reasons that motivate them to participate in biobanks. Methods: Face-to-face interviews were conducted with patients, and data were analyzed using SPSS. Results: One thousand one hundred thirty-three questionnaires were completed. The mean age of patients was 47.74 years (SD 15.26 years). More women (69%) were involved in this survey. Of the respondents, 97% had never heard of the term "biobanks." Knowledge of biobanks varied significantly with respondents' education level. Overall, 80.7% of the participants (n = 914) expressed their willingness to participate in biobanking through donation of biospecimens associated with personnel and health data. Willingness to participate in biobanks was significantly associated with gender and age. We found that the main barriers to participation in biobanks were the lack of trust in biomedical research and concerns about privacy. When asked about the preferred type of consent, the majority of patients (75%) opted for a one-time consent. Conclusion: Despite the lack of knowledge of biobanks among patients in Eastern Morocco, the majority of them expressed willingness to participate in biobanking through donation of biospecimens. However, active participation depended upon a number of factors, notably, the trust in biomedical research and privacy. Therefore, more efforts are needed to increase awareness and promote wider participation in biobanking.