One case of congenital myopathy caused by new mutation of RYR1 gene and literature review

Objective: To report a case of congenital myopathy caused by RYR1 gene complex heterozygous mutation and analyze the pathogenicity of the mutation. Method The clinical manifestation, laboratory examination, imaging findings, muscle pathology and gene test results of a child with congenital myopathy were analyzed retrospectively. Combined with literature review, it is analyzed and discussed. Result The child, female, was admitted to hospital because of "dyspnea for 22 min after asphyxia resuscitation". The main manifestations are low muscle tension, the original reflex cannot be drawn out, the trunk and proximal muscles are weak, and the tendon reflex is not drawn out. The pathological signs were negative. The electrolyte of blood liver and kidney function, blood thyroid and blood ammonia were not abnormal, and creatine kinase increased temporarily. Electromyography suggests myogenic damage. Whole exome sequencing showed that there was a new compound heterozygous variation in RYR1 gene c.14427_ 14429del/c.14138C>T.Western blot showed that the expression of RYR1 protein in patients was significantly lower than that in normal controls. Conclusion The compound heterozygous variation of RYR1 gene c.14427 was reported for the first time in China_ 14429del/c.14138c > t is the pathogenic gene of the child. The new discovery of RYR1 gene spectrum was revealed, which expanded the RYR1 gene spectrum.