The upside of a demolished chromosome

A lucky woman lost the mutated gene that had caused her rare genetic disease

DESTRUCTIVE HEALING A chromosome that shattered and reassembled — usually a calamitous event — actually healed a woman’s inherited disease.

By Tina Hesman Saey

March 17, 2015 at 1:00 pm

A shattered chromosome cured a woman of a rare genetic disease. The woman had been diagnosed as a child with WHIM syndrome, an immune disease caused by a mutation in a gene called CXCR4.

Like other WHIM syndrome patients, the woman had an extreme number of warts and was frequently hospitalized with infections. But at about age 38, those symptoms mysteriously disappeared.

Researchers at the National Institutes of Health in Bethesda, Md., examined the woman’s DNA and found that some of her blood cells were missing the mutant copy of CXCR4 and 163 other genes. In one of her blood-forming stem cells, the chromosome carrying the mutant gene had shattered and reassembled Humpty-Dumpty style, leaving out some genes, the researchers report in the Feb. 12 Cell.

Usually when chromosomes shatter, a rare process called chromothripsis (SN: 6/29/13, p. 4), it’s a catastrophe that can lead to cancer. This is the first known case of chromothripsis helping someone, and a rare case of a spontaneous cure of an inherited disease.