The search for CAG expansion in the AR gene that encodes the androgen receptor using the ExpansionHunter computer tool (a “expansion tracker”) in the genomes of 74,277 unrelated individuals shows a mutation frequency of 1/3,182 X chromosomes.
Based on this mutation frequency in the general population, the calculation of the prevalence of Kennedy’s disease increases to 1/6,888 males, a frequency 4.4 times greater than previously reported (1/30,303 or less).