ABSTRACT
Objective:To discuss the clinical features of a family with Welander distal myopathy and analyze the genetic characteristics of the T-cell intracellular antigen 1 (TIA1) gene mutation in this family.Methods:The clinical data, electrophysiological and pathological examination results of some family members were collected, and the proband was tested by next generation sequencing techniques to detect possible pathogenic mutations. Sanger sequencing was performed in some family members for the gene mutations closely related to the clinical phenotype.Results:The proband, a 30-year-old man, manifested progressive weakness and muscle atrophy in distal limbs, followed by the involvement of muscles in proximal limbs. A gene mutation of c.91G>A was detected by genetic testing in the TIA1 gene, which was associated with Welander distal myopathy. The further Sanger sequencing revealed the same mutation site in the proband′s mother, one younger brother and his youngest uncle, who showed similar symptoms as the proband including muscle weakness and atrophy. The youngest brother of the proband was a mutation carrier without obvious symptoms, and his electromyography test showed myogenic injuries.Conclusions:Welander′s distal myopathy is a slowly progressing autosomal dominant disorder, characterized by weakness and muscle atrophy mainly in the extremities. In this family, the patients showed the onset in the extremities of the lower limbs and presented weakness and atrophy in distal and proximal limbs, with disease heterogeneity among patients. Genetic testing and the analysis of the family members confirmed the diagnosis of Welander′s distal myopathy and the pathogenic mutation c.91G>A in the TIA1 gene.