Clinical and genetic characterization of female dystrophinopathy

Background and Purpose Duchenne and Becker muscular dystrophies are the most common X-linked recessive muscular dystrophies. Dystrophic gene mutations usually affect men, but reportedly 2.5–7.8% of women are affected and are classified as symptomatic carriers. The aim of this study was to clinically and genetically characterize symptomatic female dystrophi-nopathy carriers. Methods The clinical and genetic data of 11 female dystrophinopathy carriers among 285 patients who underwent multiplex ligation-dependent probe amplification (MLPA) analysis for the dystrophic gene were reviewed. Women with muscle weakness and/or dilated cardiomy-opathy were classified as symptomatic carriers, while subjects with high serum creative kinas (CK) levels and/or minor myopathic signs such as muscle cramps and malign were classified as asymptomatic. Results Twelve female carriers were identified, but 1 symptomatic carrier who also had Turner syndrome was excluded from the study. Of the 11 included female carriers, 4 were symptomatic and 7 were asymptomatic. The age at symptom onset in the symptomatic female carriers ranged from 15 to 31 years (mean, 30.6 years), and the age at diagnosis for asymptomatic carriers ranged from 4 to 38 years (mean, 24.5 years). Serum CK levels were markedly elevated (mean, 1,301 IU/mL) in three of the four (75%) symptomatic female carriers, and mildly elevated in three of the seven (42%) asymptomatic female carriers. Symptomatic female carriers typically presented with asymmetric bilateral leg weakness as the initial symptom, with aggravated symptoms afar labor. Conclusions Female dystrophinopathy is not uncommon, and it is an important factor with respect to males with dystrophinopathy who may be born to such patients. Screening with MLPA is useful because it can aid in early diagnosis and appropriate management.