PHILADELPHIA - A sperm donor passed an extremely rare and dangerous genetic
ailment to five children born to four couples, doctors reported Friday in a case
that exposes a gap in the screening process.
The disease, severe congenital neutropenia, can be fatal in children if
untreated but is so rare that sperm banks do not test for it. Moreover, the
family medical history that sperm donors must provide would not necessarily
reveal such a defect, especially if the man is only a carrier and has no
symptoms.
The four couples used the same sperm bank, said Dr. Lawrence A. Boxer, lead
author of report in The Journal of Pediatrics, a Philadelphia publication.
Boxer, director of pediatric hematology and oncology at the University of
Michigan and an expert on the disease, would not say where the sperm bank is
located, or where the donor or the recipients are from.
"The bottom line is, when you use a sperm donor you really don't know what
you're getting," Boxer said.
The researchers did not have any donor sperm to test but connected the
children's cases to one man because they all had the same version of the
defective gene and because all the couples used the same sperm bank.
Severe congenital neutropenia occurs in about one in 5 million births; Boxer
said only about 500 children in the United States have the disease. Children
with the disorder lack the type of white blood cell that kills bacteria, and as
a result develop severe infections shortly after birth.
American Society of Reproductive Medicine guidelines require anonymous sperm
donors to provide a full family medical history going back at least three
generations. The guidelines say a complete chromosome screening is not required
if a proper family history is taken concerning potential hereditary disorders.
"The question is whether a donor would even be aware that a great-grandparent
had this disease," said Scott Brubaker, policy officer for the American
Association of Tissue Banks, which accredits sperm banks. "Was this disease even
known about three generations ago?"
Sperm donors are routinely screened for more prevalent genetic disorders like
cystic fibrosis, Tay-Sachs disease and sickle cell anemia, but not for rare
genetic diseases.
It was not clear whether the sperm donor in this case knew he was a carrier.
Boxer said the sperm bank reported that the donor was healthy.
The children are doing well through daily injections of a drug that helps
build up white blood cells and fight germs, Boxer said. But they will always
have an increased risk of leukemia and a 50 percent chance of passing the
disease to their own children, he said.
