CAG expansion in exon 1 of the AR gene in Russian spinal atrophy patients

Spinal and bulbar muscular atrophy (SBMA), or Kennedy’s disease is a X-linked recessive neuromuscular disease. Its frequency is 1/ 400 000 inhabitants/year. In Russia, surveys of SBMA Kennedy on representative sets of patients have not been conducted to date. There are descriptions of only individual patients or family cases. The purpose of this research was to study the extent of CAG repeat in exon 1 of the AR gene in Russian patients. Material for this work was DNA samples isolated from the blood of 111 unrelated male with the incoming diagnosis «SBMA Kennedy’s», 5 relatives of patients, and 41 male with incoming diagnoses «Spinal muscular atrophy», whose age at the time of application was more than 30 years old and no deletions of the SMN1 gene were detected. The medical technology «System for detecting frequent mutation in Kennedy’s spinal atrophy» was introduced into the practical activity of the Research Centre for Medical Genetics. Expansion of 38 or more CAG-repeats was detected in 38 SBMA Kennedy’s patients and two patients among 41 unrelated male from SMA group. The effect of increasing the number of CAG repeats during male meiosis was shown. It was found that more than 80% of Russian patients have a poly-Q tract of 43 to 50 units, which corresponds to the classical form of SBMA with manifestation on fourth decades of lifeline rather mild progression.

спинальная и бульбарная амиотрофия Кеннеди, ген AR, экспансия CAG-повторов, антиципация, SBMA, AR, CAG-expansion, anticipation

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