A mutation in a gene called Bub1 could lead to a condition that causes disorders like Down Syndrome, pregnancy loss, and infertility, according to a study led by an Indian-origin scientist at the University of Tennessee, Knoxville.
The condition, called aneuploidy, is an abnormal number of chromosomes.
The researchers found that if a mother's egg cell has a mutation in just one copy of Bub1 gene, then she is less likely to have offspring that survive to birth.
Dr. Sundar Venkatachalam was originally studying the gene for a possible connection to colon cancer, when he found his lab mice showed strange fertility characteristics.
"Where you would normally expect a female to have eight to 10 pups, there were only one or two pups that survived to term in the litters of females that had one copy of Bub1. So this was unusual when we were looking for cancer effects, especially in this group of females," said Venkatachalam.
Ordinarily, both copies of a gene in a chromosome must carry the same mutation in order for an organism to be adversely effected, but the drastic effects of a single mutation were unexpected.
The researchers also found that the harmful effects of this mutation increased with a mother's age.
As the female mice got older, there was eventually a complete loss of their ability to support a full-term pregnancy that lined up with an increase in aneuploidy.