Doctors report that a single sperm donor has transmitted a rare and serious genetic disease to five children conceived through in vitro fertilization.

These cases show that even with careful screening of sperm donors genetic disorders can be transmitted to children conceived through fertility procedures.

“At present it is difficult to screen for all conceivable genetic disorders, thus extensive preconception counseling is a must and should never be omitted,” write Dr. Laurence A. Boxer from the University of Michigan in Ann Arbor and colleagues report in The Journal of Pediatrics.

All five children developed severe congenital neutropenia (SCN) - a rare genetic disorder characterized by abnormally low levels of important infection-fighting white blood cells, leaving them vulnerable to infection and at heightened risk of developing leukemia, a blood cancer.

The outlook for children with SCN has improved “dramatically” with the development of a drug called G-CSF, which has proven very effective in raising white blood cell counts and reducing the occurrence of infections.

SCN is attributed to mutations in the ELA2 gene. Advanced genetic testing revealed that none of the mothers had a mutation in ELA2, but the sperm donor who fathered the children did and all five children with SCN had the exact same mutation as the father.

The evidence was “very strong for a single common parent of origin” based on sequencing of the ELA2 gene and other genetic studies, the researchers report.

The sperm bank has been informed of this evidence and all remaining sperm samples from this particular donor have been discarded. The donor himself has been notified that he is no longer qualified to donate sperm.

SOURCE: The Journal of Pediatrics May 2006.