Investigation of a family with Kennedy disease by genetic analysis

Abstract

To report on a Chinese family from Wenzhou with genetically confirmed Kennedy disease and describe its clinical and genetic features. The clinical phenotype and the level of relevant biochemical markers were assessed. To determine the number of CAG repeats in the exon 1 of androgen receptor (AR) gene, genomic DNA was extracted from peripheral blood samples of the family members, amplified by PCR and identified by DNA sequencing. The proband showed predominantly proximal limb weakness, fasciculation, muscle atrophy, gynecomastia, sexual dysfunction and increased serum creatine kinase. Myopathy and neuropathy were identified by electromyography. Two other affected males and 2 affected female carriers were identified to carry an expanded CAG repeat in the AR gene. The numbers of CAG repeats were found to be 43 in the proband, 43 and 42 in the other two affected males, one of which had similar clinical symptoms to the proband. The family was diagnosed with Kennedy disease by analysis of the AR gene.