Gene linked to inherited glaucoma.

Scientists at Stanford (Calif.) University and the University of Michigan, Ann Arbor, have identified a gene involved in some cases of inherited glaucoma. The same gene, LMX1B, is responsible for a rare inherited disease called nail-patella syndrome (NPS), which causes malformed fingernails, toenails, kneecaps, and elbows. The findings confirm the researchers' earlier proposal that the two sets of symptoms in these patients spring from the same genetic defect.

Glaucoma is the second leading cause of blindness worldwide. In the U.S., it affects more than 2,500,000 people, half of whom do not know they have the disease. Increased pressure in the eye is thought to destroy nerve cells, leading to glaucoma's characteristic patterns of vision loss. Although it appears that no single gene defect is responsible for most cases of glaucoma, scientists suspect that the disease usually is spurred by genetic components in addition to environmental effects.

Physical defects associated with nail-patella syndrome vary from one patient to another. The skeletal abnormalities, usually recognizable at birth, can be severe or mild. Some patients also have kidney problems...