First application of next-generation sequencing in four families with Wilson disease in Morocco

Abstract Background Wilson disease is a rare autosomal recessive disorder characterized by toxic accumulation of copper in various organs, principally in the liver and brain. The disease can be manifested with hepatic, neurologic and ophthalmic signs and in a rare case with psychiatric, hematological, renal and skeletal signs; symptoms vary among and within families. Traditionally, Wilson disease was diagnosed on the basis of biochemical markers which include low ceruloplasmin levels and elevated urinary and hepatic copper. However, theses parameters are not specific and can been seen in other disorders. Genetic testing is now considering the most specific test allowing a precise diagnosis. In this study, we report the results of molecular analysis of four unrelated patients with Wilson disease from Morocco; we used a next-generation sequencing customized multigene panel to investigate the ATP7B gene for the four unrelated patients with Wilson disease. Results Genetic tests based on next-generation sequencing allow to the identification of four previously described variants. One in compound heterozygous state and three at homozygous state. Conclusions Our results confirm the clinical diagnosis of Wilson disease in these reported families and have implications for their genetic counselling and clinical management. Diagnosis of Wilson disease is a major challenge in clinical practice, and Genetic testing of ATP7B gene should be recommended in patients with suspected Wilson disease

Next generation sequencing identifies a pathogenic mutation of WFS1 gene in a Moroccan family with Wolfram syndrome: a case report

Abstract Background Wolfram syndrome is a rare autosomal recessive neurodegenerative disorder that affects 1/200,000 to 1/1,000,000 children. It is characterized by juvenile onset diabetes, optic nerve atrophy and other systemic manifestations. Symptoms of the disease arise mostly in early childhood with a high mortality rate due to severe neurological complications. Two causative genes have been identifed in this syndrome; the classical form is caused by autosomal recessive mutations of the WFS1 gene, and a smaller portion of patients has mutations in the CIDS2 gene, which are responsible for autosomal recessive Wolfram syndrome 2. Case presentation We report the case of a 28-year-old Moroccan boy born from consanguineous parents referred to the department of medical genetics at the National Institute of Health in Rabat. The diagnosis of Wolfram syndrome was made based on insulin-dependent diabetes, optic nerve atrophy, sensorineural deafness, urological abnormalities and psychiatric illness. To establish the diagnosis at a molecular level, we performed next-generation sequencing in the index patient, which revealed compound heterozygous WFS1 mutations: c.1113G > A (p.Trp371Ter) and c.1223_1224insGGAACCACCTGGAGCCCTATGCCCATTT (p.Phe408fs). This second variant has never been described in patients with Wolfram syndrome. Conclusion The identification of the genetic substrate in our patient confirmed the clinical diagnosis of Wolfram syndrome and allowed us to provide him an appropriate management and genetic counseling to his family

Post-mortem diagnosis of Pompe disease by exome sequencing in a Moroccan family: a case report

Abstract Background Pompe disease is an autosomal recessive lysosomal storage disorder characterized by progressive myopathy with proximal muscle weakness, respiratory muscle dysfunction, and cardiomyopathy. Its prevalence ranges between 1/9000 and 1/40,000. It is caused by compound heterozygous or homozygous mutations in the GAA gene, which encodes for the lysosomal enzyme alpha-glucosidase, required for the degrading of lysosomal glycogen. Case presentation In this study, we report the case of a Moroccan consanguineous family with hypertrophic cardiomyopathy and sudden cardiac deaths at an early age; our patient was a 7-month-old Moroccan girl. Whole exome sequencing identified the deleterious homozygous mutation c.236_246delCCACACAGTGC (p.Pro79ArgfsX13) of GAA gene leading to a post-mortem diagnosis of Pompe disease. Conclusion The identification of the genetic substrate in our patient, the daughter, confirmed the clinical diagnosis of Pompe disease and allowed us to provide appropriate genetic counseling to the family for future pregnancies