Ataxia-telangiectasia is an inherited disease. People with this disease begin having problems with balance and walking during early childhood. To have the disease, a person needs to inherit two copies of the abnormal gene, one from each parent.
Carriers have only one copy of the abnormal gene.
Previous studies have shown that carriers of the ataxia-telangiectasia gene have a higher risk for cancer and, possibly, heart disease than persons who do not carry this gene. However, it is unknown whether persons who carry this gene actually have higher death rates than noncarriers. To find out whether persons who carry one copy of the abnormal gene for ataxia-telangiectasia have higher death rates than the general population. The study included 405 grandparents of persons with ataxia-telangiectasia. The researchers tested the grandparents to determine who carried one abnormal copy of the gene.