Inashkina Inna, Jankevics Eriks, Stavusis Janis, Vasiljeva Inta, Viksne Kristine, Micule Ieva, Strautmanis Jurgis, Naudina Maruta S, Cimbalistiene Loreta, Kucinskas Vaidutis, Krumina Astrida, Utkus Algirdas, Burnyte Birute, Matuleviciene Ausra, Lace Baiba
Biomedical Research and Study Centre, Ratsupites str. 1, k-1, LV-1067, Riga, Latvia.
Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University, Vilnius, Lithuania.
BMC Musculoskelet Disord. 2016 May 4;17:200. doi: 10.1186/s12891-016-1058-z.
Limb-girdle muscular dystrophies are characterized by predominant involvement of the shoulder and pelvic girdle and trunk muscle groups. Currently, there are 31 genes implicated in the different forms of limb-girdle muscular dystrophies, which exhibit similar phenotypes and clinical overlap; therefore, advanced molecular techniques are required to achieve differential diagnosis.
We investigated 26 patients from Latvia and 34 patients from Lithuania with clinical symptoms of limb-girdle muscular dystrophies, along with 565 healthy unrelated controls from general and ethnic populations using our developed test kit based on the Illumina VeraCode GoldenGate genotyping platform, Ion AmpliSeq Inherited Disease Panel and direct sequencing of mutations in calpain 3 (CAPN3), anoctamin 5 (ANO5) and fukutin related protein (FKRP) genes.
Analysis revealed a homozygous CAPN3 c.550delA mutation in eight patients and three heterozygous variants in controls: dysferlin (DYSF) c.5028delG, CAPN3 c.2288A > G, and FKRP c.135C > T. Additionally, three mutations within FKRP gene were found: homozygous c.826C > A, and two compound - c.826C > A/c.404_405insT and c.826C > A/c.204_206delCTC mutations, and one mutation within CLCN1 gene - c.2680C > T p.Arg894Ter. ANO5 c.191dupA was not present.
Genetic diagnosis was possible in 12 of 60 patients (20%). The allele frequency of CAPN3 gene mutation c.550delA in Latvia is 0.0016 and in Lithuania - 0.0029. The allele frequencies of CAPN3 gene mutation c.2288A > G and DYSF gene mutation c.4872delG are 0.003.
肢带型肌营养不良症的特征是肩部、骨盆带和躯干肌群受累为主。目前，有31个基因与不同形式的肢带型肌营养不良症相关，这些病症表现出相似的表型和临床重叠；因此，需要先进的分子技术来进行鉴别诊断。
我们使用基于Illumina VeraCode GoldenGate基因分型平台、Ion AmpliSeq遗传性疾病检测板以及钙蛋白酶3（CAPN3）、anoctamin 5（ANO5）和福金相关蛋白（FKRP）基因突变直接测序开发的检测试剂盒，对来自拉脱维亚的26例和来自立陶宛的34例有肢带型肌营养不良症临床症状的患者，以及来自普通和特定族群的565名健康无关对照进行了研究。
分析发现8例患者存在纯合的CAPN3 c.550delA突变，对照中有3个杂合变异：肌膜蛋白（DYSF）c.5028delG、CAPN3 c.2288A＞G和FKRP c.135C＞T。此外，在FKRP基因中发现了3个突变：纯合的c.826C＞A，以及两个复合突变——c.826C＞A/c.404_405insT和c.826C＞A/c.204_206delCTC突变，在CLCN1基因中发现了1个突变——c.2680C＞T p.Arg894Ter。未发现ANO5 c.191dupA。
60例患者中有12例（20%）实现了基因诊断。拉脱维亚CAPN3基因突变c.550delA的等位基因频率为0.0016，立陶宛为0.0029。CAPN3基因突变c.2288A＞G和DYSF基因突变c.4872delG的等位基因频率均为0.003。
