Chromosomal abnormalities in 163 Tunisian couples with recurrent miscarriages

Recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses before 24 weeks of gestation. Parental chromosomal abnormalities represent an important etiology of RM. The aim of the present study was to identify the distribution of chromosome abnormalities among Tunisian couples with RM referred to the Department of Cytogenetic at the Pasteur Institute of Tunis (Tunisia) during the last five years. Standard cytogenetic analysis was carried out in a total of 163 couples presenting with two or more spontaneous abortions. Karyotypes were analyzed by R-banding. We identified 14 chromosomal abnormalities including autosomal reciprocal translocation, Robertsonian translocation, inversion, mosaic aneuploidy and heteromorphysm. The overall prevalence of chromosomal abnormalities was 8.5% in our cohort. This finding underlies the importance of cytogenetic investigations in the routine management of RM

Cytogenetic and molecular diagnosis of Fanconi anemia revealed two hidden phenotypes: Disorder of sex development and cerebro‐oculo‐facio‐skeletal syndrome

International audienceBackground: Several studies have shown a high rate of consanguinity and endogamy in North African populations. As a result, the frequency of autosomal recessive diseases is relatively high in the region with the co-occurrence of two or more diseases.Methods: We report here on a consanguineous Libyan family whose child was initially diagnosed as presenting Fanconi anemia (FA) with uncommon skeletal deformities. The chromosome breakage test has been performed using mitomycin C (MMC) while molecular analysis was performed by a combined approach of linkage analysis and whole exome sequencing.Results: Cytogenetic analyses showed that the karyotype of the female patient is 46,XY suggesting the diagnosis of a disorder of sex development (DSD). By looking at the genetic etiology of FA and DSD, we have identified p.[Arg798*];[Arg798*] mutation in FANCJ (OMIM #605882) gene responsible for FA and p.[Arg108*];[Arg1497Trp] in EFCAB6 (Gene #64800) gene responsible for DSD. In addition, we have incidentally discovered a novel mutation p.[Gly1372Arg];[Gly1372Arg] in the ERCC6 (CSB) (OMIM #609413) gene responsible for COFS that might explain the atypical severe skeletal deformities.Conclusion: The co-occurrence of clinical and overlapping genetic heterogeneous entities should be taken into consideration for better molecular and genetic counselin