OBJECTIVETo analyze clinical characteristics of a combination of dystrophinopathies and Klinefelter's syndrome (karyotype 47, XXY) in one patient.

METHODThe patient was diagnosed as Duchenne muscular dystrophy (DMD) and Klinefelter's syndrome in Beijing Children's Hospital in March, 2013. The clinical manifestations, physical examinations and laboratory test results were analyzed respectively. The clinical characteristics of four cases reported previously were analyzed as well.

RESULTThe 8.5 years old boy presented with symptoms of walking disorder and developmental delay. The patient had facial dysmorphism, waddling gait, Gower's manoeuvre and enlarged calves.Serum creatine kinase level was 21 040 U/L, and he had mild intellectual impairment. Deletions of exons 49-54 of the dystrophin gene were found.Gene dosage analysis revealed a heterozygous deletion in his mother. Five cases have been reported till now, their age ranged from 3.5 to 18 years; 3 of them were DMD, while the other 2 cases were Becker muscular dystrophy (BMD). One of them, detected in pedigree study, whose weakness was minimal in contrast to the proband. The others came to the hospital because of walking disorder or developmental delay. All the patients had enlarged calves, some of them also had Gower's manoeuvre and waddling gait. The patients' height was between 3 rd and 50 th percentile, while 2 of them had facial dysmorphism.Some degree of mental impairment is usual. Their serum creatine kinase were 2 469-24 750 U/L.One of them was detected in pedigree study. Three of them were diagnosed by muscle biopsy, while in the other one mutation analysis was used.

CONCLUSIONThe combination of dystrophinopathies and Klinefelter's syndrome is quite rare, and has clinical features of these two diseases. Mutation analysis (or muscle biopsy) and karyotype analysis can finally diagnose the syndrome.