A rare form of limb girdle muscular dystrophy (type 2E) seen in an Iranian family detected by autozygosity mapping

作者：Mojbafan Marzieh; Nilipour Yalda; Tonekaboni Seyed Hasan; Bagheri Samira Dabbagh; Bagherian Hamideh; Sharifi Zohreh; Zeinali Zahra; Tavakkoly Bazzaz Javad; Zeinali Sirous

来源：Journal of Neurogenetics, 2016, 30(1): 1-4.

DOI：10.3109/01677063.2016.1141208

• Autozygosity mapping
• beta sarcoglycanopathy
• limb girdle muscular dystrophy
• mutation analysis

Sarcoglycanopathies (SGPs) constitute a subgroup of autosomal recessive limb girdle muscular dystrophies (LGMDs) which are caused by mutations in sarcoglycan (SGs) genes. SG proteins form a core complex consisting of alpha, beta, gamma and delta sarcoglycans which are encoded by SGCA, SGCB, SGCG and SGCD genes, respectively. Genetic defect, in any of these SG proteins, results in instability of the whole complex. This effect can be helpful in interpreting muscle biopsy results. Autozygosity mapping is a gene mapping approach which can be applied in large consanguineous families for tracking the defective gene in most autosomal recessive disorders. In the present study, we used autozygosity mapping, to find the gene responsible for muscular dystrophy. Proband was a 10-year-old boy referred to our center for ruling out DMD (Duchenne muscular dystrophy). According to the pedigree and clinical reports, we assessed him for SGPs. Haplotyping, using the four short tandem repeat (STR) markers for each of the SG genes, showed that the phenotype may segregate with SGCB gene; and observing two crossing overs which occurred within the gene suggested that the mutation might be in the first two exons of SGCB gene. Mutation analysis showed a 26bp duplication (10bp before the initiation codon till 13bp after the ATG start codon). This will cause a frameshift in protein synthesis.

• 出版日期2016