Balci B, Wilichowski E, Haliloğlu G, Talim B, Aurino S, Kremer E, Ebinger F, Senbil N, Anlar B, Kale G, Nigro V, Topaloğlu H, Bonnemann C, Dinçer P
Hacettepe University, Faculty of Medicine, Department of Medical Biology, Turkey.
Acta Myol. 2004 Dec;23(3):154-8.
The term limb-girdle muscular dystrophy (LGMD) refers to a group of muscular dystrophies that, at the outset, affect primarily the muscles of the hip and shoulder girdle. Limb-girdle muscular dystrophy is genetically heterogeneous comprising autosomal dominant (types LGMD 1A-1E) as well as autosomal recessive forms (types LGMD 2A-2J known). A subgroup among the autosomal recessive forms comprises the sarcoglycanopathies (LGMD2C-2F), caused by mutations in the gamma (gamma-SG), alpha (alpha-SG), beta (beta-SG) and delta (delta-SG) sarcoglycan genes, respectively. The sarcoglycans form the sarcoglycan complex, part of the dystrophin-associated glycoproteins. Mutations in the beta-SG gene causes LGMD2E. Disease severity, in this form, varies from mild to severe phenotypes depending on the individual mutation. Homozygous missense mutations in critical locations may result in the total absence of alpha-, beta- and gamma-sarcoglycan from the muscle membrane and a phenotype as severe as null mutations. In the present study, through screening 80 unrelated LGMD2 families, we identified 13 families with LGMD2E. Mutations in the beta-SG gene were identified in 12 patients from nine families. One of these patients carried a previously reported truncating mutation (Q11X), while the other 11 carried novel missense/rameshift mutations (M1L, V89M, I92T, I92S, 739insA), some of which were seen in more than one patient and may, therefore, be more common in the Turkish population.
肢带型肌营养不良症（LGMD）是指一组肌营养不良症，起初主要影响髋带和肩带的肌肉。肢带型肌营养不良症在遗传上具有异质性，包括常染色体显性（LGMD 1A - 1E型）以及常染色体隐性形式（已知LGMD 2A - 2J型）。常染色体隐性形式中的一个亚组包括肌聚糖病（LGMD2C - 2F），分别由γ（γ - SG）、α（α - SG）、β（β - SG）和δ（δ - SG）肌聚糖基因突变引起。肌聚糖形成肌聚糖复合物，是肌营养不良蛋白相关糖蛋白的一部分。β - SG基因突变导致LGMD2E。在这种形式中，疾病严重程度因个体突变而异，从轻度到重度表型不等。关键位置的纯合错义突变可能导致肌膜完全缺失α - 、β - 和γ - 肌聚糖，并产生与无效突变一样严重的表型。在本研究中，通过筛查80个无关的LGMD2家族，我们鉴定出13个LGMD2E家族。在来自9个家族的12名患者中鉴定出β - SG基因突变。其中一名患者携带先前报道的截短突变（Q11X），而其他11名患者携带新的错义/移码突变（M1L、V89M、I92T、I92S、739insA），其中一些在不止一名患者中出现，因此可能在土耳其人群中更常见。
