Late-Appearing Defects

Not all inherited disorders are apparent at birth. Many errors of body chemistry can cause damage before symptoms appear. If such a disorder runs in your family, it would be wise to seek genetic counseling to find out if you or your children could be at risk. Sometimes physicians and parents can be alerted to test an nindividual in the family early and treat him or her to prevent progressive damage.

In many defects that are not evident at birth, the age at which symptoms appear varies widely. Some of the more familiar disorders and the ages at which they usually are diagnosed include:

• Cystic fibrosis: a disorder of the lungs and digestive system, birth to 4 years
• Tay-Sachs disease: devastating mental retardation, 6 months to 1 year
• Sickle cell disease: a blood disorder, from 6 months on (can be detected with routine newborn screening)
• Duchenne muscular dystrophy: a muscle-wasting disease, 2-4 years
• Di George/velocardiofacial syndrome: a heart, immune and speech disorder, 4-8 years
• Glaucoma: dangerous pressure buildup inside the eye, from late 30s on
• Gaucher disease: involves the liver, spleen and bone marrow, usually from childhood on