Fragile X syndrome (FXS) has been reported as the leading cause of mental retardation (MR) that predominantly involves males compared to females. An over-expansion of CGG repeats in the 5′ untranslated region of the FMR1 gene plays the primary role in this disease. In this study, we encountered a homozygote female patient affected by FMR1 expansion mutation. Surprisingly, she had inherited her fullmutated alleles from two different ancestors. This condition is an extremely rare case of FXS. After accurate genetic counseling, family members were referred to the laboratory for genetic testing. Karyotype with two X chromosomes was the finding after the G-banding study of the proband.Molecular analysis indicated that she was a female with full-mutated or pre-mutated alleles on both of her X chromosomes. It is a rare phenomenon that we detected in this patient. We have concluded that a combination of allele instability during oogenesis and inheritance of two alleles are the leading cause of MR in the presented case.
Jalili syndrome (JS) is a rare autosomal recessive with two cardinal symptoms including cone-rod dystrophy (CRD) and amelogenesis imperfecta (AI). This disease caused by different mutations on the metal transporter gene CNNM4 located on 2q11. This report described an Iranian family with clinical features of JS and phenotypic variability in terms of ocular and dental findings. The parents were healthy and consanguineous, but three out of their four offspring shared an oculo-dental phenotype. Dental and ocular examination shows CRD and AI. Enamel destruction and Ocular symptoms began in their childhood. Whole exome sequencing (WES) in the proband identified a novel homozygous mutation (c.G1423A:p.V475M) in the CNNM4 gene. These findings suggested that the p.V475M mutation in homozygous state induces a complete phenotype with both CRD and AI.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.