A disorder of carbohydrate metabolism. Diagnosis and dietary treatment from birth results in improvement of physical effects and normal or near normal growth and development. In untreated cases, features include: weight loss, jaundice, anaemia, enlargement of liver, cataracts, weakness, lax muscle tone, loss of skills due to neurological deterioration. Autosomal recessive inheritance.

A disease present at birth caused by a genetic lack of an enzyme needed to metabolize galactose into glucose. May result in mental retardation, cataracts and liver damage.