Kennedy’s Disease (SBMA)

Spino-bulbar muscular atrophy (SBMA) or Kennedy’s disease (KD) is a sex-linked recessive neurodegenerative disorder, which is progressively manifested and affects males only with a frequency of ~1/50.000. The disorder results in loss of motor neurons of the extremities, as well as of the head and is characterized by progressive muscular atrophy as well as gynecomastia and testicular atrophy, ultimately leading to infertility. All affected individuals exhibit a pathological increase of the number of CAG triplet repeats in the androgen receptor (AR) gene on chromosome Xq11-q12.


A special multiplex polymerase chain reaction (PCR) is applied, for the detection of the precise number of CAG triplet repeats in the androgen receptor (AR) gene. For all prenatal molecular genetic testing, we perform analysis of polymorphic STR markers from a maternal blood sample and the fetal sample, in order to exclude any possible maternal cell contamination. Thus, for prenatal diagnosis, 1-2ml of a maternal blood sample should always accompany the fetal sample (amniotic fluid or CVS).