目的 提高对肢带型肌营养不良2D型临床及基因型特征的认识。方法 回顾分析1例肢带型肌营养不良 2D型患儿的临床资料,并复习相关文献。结果 男性患儿, 5岁7个月起病。有进行性肌无力、腓肠肌肥大、Gower征阳性。 磷酸肌酸激酶20 602 U/L;肌电图示肌源性损害;肌肉磁共振示双下肢皮下脂肪层及肌肉内见条片状压脂序列高信号,肌 肉层著。MLPA检测DMD基因阴性;全外显子测序示SGCA基因第3外显子c.234-235AC>GA纯合突变,该位点未见报道, 美国医学遗传学与基因组学学会(ACMG)评级为致病性变异,其父母均为杂合携带。患儿最终诊断为肢带型肌营养不良 2D型。结论 SGCA c.234-235AC>GA变异可能为肢带型肌营养不良2D型新的致病性突变。肌酶明显升高时,除假肥大 型肌营养不良症外,还应注意肢带型肌营养不良2D型。
Objective To improve the understanding of the clinical and genotypic characteristics of limb-girdle muscular dystrophy type 2D (LGMD2D). Methods The clinical manifestations, laboratory tests, electromyography, muscle MRI and genetic test results of a patient with LGMD2D were retrospectively analyzed, and the related literature were reviewed. Results The patient was a 5 years and 7 months old male, who presented with progressive muscle weakness, gastrocnemius hypertrophy, Gower sign positive, phosphocreatine kinase 20602 U/L, electromyography showed myogenic damage, muscle MRI showed a high signal of double lower limb subcutaneous fat layer and the muscles on the fat suppressed sequence, and the muscles were more obvious. The MLPA result of Duchenne muscular dystrophy (DMD) gene test was negative, and the whole exom sequencing showed a homozygous c.234-235AC>GA mutation in exon 3 of SGCA gene which has not been reported. According to ACMG rating, this variant was pathogenic, and his parents were all heterozygous carriers. The patient was diagnosed as LGMD2D. Conclusion SGCA c.234-235AC>GA variation may be a novel pathogenic mutation in LGMD2D. For children with clinically suspected muscular dystrophy and significantly increased muscle enzyme, in addition to DMD, we should also pay attention to the LGMD2D.