[Clinical features and genetic diagnosis of Kennedy disease]

To outline the clinical features of Kennedy disease in Chinese patients.

The peripheral blood was collected from the male lower motor neuron disease patients of our inpatients and outpatients from July 2005 to September 2008. Then the genome DNA was extracted and the target gene amplified by polymerase chain reaction and sequenced. The clinical data of positive samples were analyzed and summarized.

The number of expanded CAG repeats of 12 patients ranged from 43 to 57. And the number of CAG repeats was inversely correlated with the age of onset (r = -0.756, P < 0.005). The first symptom of all of these patients was extremity weakness. The progression of disease was slow. One of the patients died from pneumonia. And the whole disease course lasted for 14 years.

As an adult onset degenerative disease with a slower clinical progression, Kennedy disease has its own characteristics of inheritance pattern and natural course. It can be accurately diagnosed by androgen receptor gene analysis.