By Shaun Griffin, PhD
NEW YORK, Dec 24 (Reuters Health) -- A specific mutation on the Y (male)
chromosome may be a cause of impaired sperm production in some men, according to
researchers.
"In recent years, we've come to understand that the Y chromosome is
critical in making sperm, and that defects in the Y chromosome cause infertility
in many men," explained study senior author Dr. David C. Page, of the
Massachusetts Institute of Technology in Boston. The findings are published in
the December issue of the journal Nature Genetics.
Previous studies have indicated that mutations in one of three regions on
the Y chromosome can cause subfertility (impaired fertility) or infertility in
affected men.
In their study, the Boston researchers sought out Y chromosome mutations
in the genetic material of nearly 600 men who were diagnosed as being subfertile
due to problems producing sperm.
Focusing their efforts on one of the three suspect regions of the Y
chromosome, the investigators found that mutations in the USP9Y gene appeared to
be associated with subfertility.
According to the investigators, the mutation "was present in a
(subfertile) man... but absent in his fertile brother," pointing to the mutation
as the probable cause of subfertility.
The discovery of specific genetic mutations as a cause of subfertility may
be a first step in devising gene-oriented therapies aimed at correcting the
disorder. In an interview with Reuters Health, Page said, "Until now, we'd not
seen a 'smoking gun' -- a new mutation -- implicating a specific Y-chromosome
gene in male infertility."
"We are only at the beginning of this story," he added. "There will be
more smoking guns to be found in other genes, on the Y chromosome and elsewhere,
in the future."
