Problem:
Devon died at age 16 of Lowe syndrome. He had slight intellectual disability, visual problems (cataracts and glaucoma), seizures, poor muscle tone, and progressive kidney failure, which was ultimately fatal. His sister Lily is pregnant, and wonders whether she is a carrier of the disease that killed her brother. She remembers a doctor saying that her mother Drucilla was a carrier. Lily's physician determines that she is a carrier because she has cataracts, which is a clouding of the lenses. It has not yet affected her vision. When a prenatal test reveals that Lily's fetus is a female, her doctor tells her not to worry about Lowe syndrome.