ABSTRACT
Objective:To explore the phenotypic and genotypic characteristics of 3 Chinese families with dystrophinopathy, so as to provide the data for earlier diagnosis and therapy.Methods:The clinical, muscle pathology and electrophysiological data from the 3 families with dystrophinopathy were analyzed.The perpheral venous blood of 15 members from the 3 families was collected.Meanwhile, the known genes that were related to neuromyopathy were detected.Results:There were 8 patients in the 3 families.All the patients presented progressive weakness of extremities as the main manifestation, with elevated creatine kinase (CK) and myogenic changes in electrophysiological examination.The proband of family 1 was a 15 years old boy with 1 year history.He displayed limb weakness and accompanied with muscle pain after exercise.Muscle pathology only revealed denatured and atrophy muscle fibers, without necrosis and hyperplastic muscle fibers.The proband of family 2 was a 9 years old boy with 1 year history.His muscle pathology illustrated degeneration, necrosis, proliferation and lipid deposition muscle fibers.The proband of family 3 was a 16 years old boy with 10 years history.He exhibited generalized muscle atrophy, spine and chest deformity.His muscle pathology demonstrated classical muscular dystrophy changes.Gene detection gave information that deletion mutation in exons 45 to 47 of DMD gene in family 1 proband.c.2636 T> G mutation in exons 18 of DMD gene in family 2 proband, repeat mutation in exons 61 to 76 of DMD gene in family 3 proband; c.2636T>G was classified as pathogenic variation according to the guidelines for the interpretation of sequence variants of the American college of medical genetics and genomics guidelines. Conclusions:The phenotype of dystrophinopathy is related to genotype.A new mutation of DMD gene c. 2636T>G is discovered.Early patient with dystrophinopathy can only display pained weakness of muscle after exercise.Muscle pathology and gene detection should be performed as soon as possible.