fwd fyi... Lindsay
Monday 21 February 2000
Infertility cure for men may be close
By Penny Fannin
Male infertility has been "cured" in experiments on mice and the
technology could be available for use on humans within a decade.
The infertility cure, a technique called spermatogonial
trans-plantation, was reported in the journal Nature Medicine last
At a gene technology forum this week Professor Roger Short, Wexler
professorial fellow in the department of obstetrics and gynaecology at
the University of Melbourne, said the community should consider how far
it wants to go in curing infertility.
As reproductive techniques advanced, the community and regulators were
being asked to make increasingly complex and life-changing decisions,
Professor Short said male infertility often occurred because men had
mutations or deletions in the genes that control sperm production.
Techniques already exist, and have been used, that allow abnormal sperm
to be injected into eggs. "In allowing defective sperm to fertilise an
egg in this way, we know that we are propagating the defect in any male
offspring that are produced," Professor Short said.
Although the offspring's fertility could be treated in a similar way,
Professor Short questioned whether treating infertility outweighed
concerns about adverse effects in the population at large.
The use of spermatogonial transplantation, as detailed in the Nature
paper, raises other ethical questions. Restoring fertility using
spermatogonial transplantation is not like artificial insemination -
where a donor's sperm is used - as it involves the transfer of germ
cells, the cells that differentiate into sperm or eggs.
This new technique means that once the germ cells of man X are
transplanted into the testes of man Y (who is infertile), man Y will
make the sperm of man X for the rest of his life and all his children
will have the genetic make-up of man X, Professor Short said.
The authors of the Nature Medicine study said spermatogonial
transplantation could be used to treat animal or human infertility and
have applications for patients whose sperm production has been affected
by radiation or chemotherapy.
They estimate about 50 per cent of human infertility is due to male
"defects" and that 70 to 90 per cent of these defects arise from
impaired sperm production.
But Professor Short said the advances being made in treating male
infertility with germ cell transplantation would benefit only a small
percentage of the world's population - those with access to money and
The acting director of the Murdoch Institute ethics unit, Dr David
McCarthy, said if this technique was practised, people would expect the
donor's consent to be given for his germ cells to be used in this way.
The technique also allowed men to impregnate their partners in a
"natural" way, he said.
In the Nature paper, germ cells were moved from one male into another,
but it is possible to actually alter a person's germ cells. Professor
Short said most regulatory authorities had agreed not to manipulate
human germ cells.
"Once we have tampered with the genetic make-up of the gametes (sperm
and eggs) that we produce, the genie is out of the bottle and we could
inadvertently end up by changing the genetic make-up of our species
forever," he said.