Diagnosis and genetic analysis of a case with glycogen storage disease type V caused by compound heterozygous mutations in the PYGM gene.

Glycogen storage disease type V is an autosomal recessive genetic disorder caused by muscle glycogen phosphorylase (PYGM) deficiency, which is characterized by exercise intolerance, second wind phenomena and high level of serum creatine kinase. In this study, we reported a Chinese young man with glycogen storage disease type V, with lower extremity weakness after exercise, increased creatine kinase, and slight fat infiltration in the posterior group of thigh muscle by magnetic resonance imaging (MRI). The proband had complex heterozygous PYGM disease-causing mutations, including c.308T>C (p.L103P) variant transmitted from the mother and c.260_261delCT (p.S87Ffs*23) from the father, of which the former was a novel PYGM mutation. This study enriched the PYGM pathogenic gene mutation spectrum, contributed to improve clinicians' understanding of glycogen storage disease type V and provided a reference for further genetic study of the disease.糖原累积症V型是一种由肌糖原磷酸化酶(muscle glycogen phosphorylase，PYGM)缺陷引起的常染色体隐性遗传疾病，其临床特征为运动不耐受、再振作现象和血清肌酸激酶水平增高。本文报道了1例中国糖原累积症V型年轻男性患者，运动后双下肢无力、血肌酸激酶升高、肌肉磁共振可见下肢近端后群肌轻度脂肪浸润，基因检测结果显示先证者具有复合杂合型PYGM致病突变，分别为来自母亲的c.308T>C (p.L103P)变异和来自父亲的c.260_261delCT (p.S87Ffs*23)变异，其中前者为新发突变。本研究丰富了PYGM致病基因突变谱，有助于提高临床医生对糖原累积症V型的认识，并为该疾病的进一步遗传学研究提供参考。.