Genotype and clinical phenotype analysis of a Family with Kennedy disease

Abstract

To investigate the clinical phenotype-genotype correlations of a family with Kennedy disease (KD) and improve our understanding of the disease. KD was confirmed after clinical phenotypic analyses, laboratory tests, polymerase chain reaction assays for cytosine-adenine-guanine (CAG) repeats, and neuro-electrophysiological tests. The disease was assessed using the KD1234 scale and the spinal and bulbar muscular atrophy functional rating scale. The average age of disease onset was 30.8 ± 2.85 years. Clinically diagnosed members had 48 CAG repeats (≥35 is abnormal) in the androgen receptor gene. The patients exhibited gynecomastia and testicular dysfunction. The lesions mainly involved the medulla oblongata and spinal cord. Progesterone and serum creatine kinase levels were significantly high. Electromyography showed chronic neurogenic damage and abnormal sensory and motor conduction in family members who did not participate in sports, exercise, or physical hobbies. Our study showed that this family had a stable inheritance of CAG repeats, and the genotype was consistent with the clinical phenotype. Gynecomastia was the first symptom, with progressive androgen resistance resulting in testicular atrophy, infertility, and sexual dysfunction. Changes in serum creatine kinase may indicate the progression or relief of symptoms, and rehabilitation may delay the progression of muscle atrophy.