[Molecular diagnosis for a patient with Kennedy disease].

OBJECTIVE

To screen for potential mutations of androgen receptor (AR) gene in a patient clinically diagnosed as Kennedy disease.

METHODS

Polyglutamine expansion (PQE) induced by a duplication of CAG trinucleotide tandem-repeat in exon 1 of the AR gene was detected with PCR and T-clone sequencing.

RESULTS

Compared with the number of CAG repeat of 22 in the normal allele, the number of CAG repeats has increased to 45 in the mutant allele carried by the patient. This has fit with the diagnostic criteria for Kennedy disease.

CONCLUSION

A mutation of PQE has been detected in the patient with Kennedy disease. Detection of PQE in AR gene can be used as reliable method to identify the Kennedy disease.