Familial hypo-retinol-binding proteinemia found in a child with keratomalacia

Retinol-binding protein (RBP) is a plasma protein with a molecular weight of 21,000 synthesized in the hepatocytes, binds with retinol (vitamin A), and transports it to peripheral tissues. Keratomalacia is caused by deficiency of vitamin A itself and/or protein-calorie malnutrition in the latter of which production of RBP is inhibited. We found for the first time familial hypo-retinol-binding proteinemia in a child at an age of 19 months who developed keratomalacia during measles infection in spite of good nourishment. The patient, her sister and mother showed persistent low levels, about half the normal levels of retinol and RBP which were unresponsive to oral vitamin A and protein diet. But they had normal liver function tests, normal levels of the other serum proteins, lipids, and fat-soluble vitamins. This hypo-retinol binding proteinemia was thought to predispose the child to develop keratomalacia during measles. The family members involved would be heterozygous for the normal gene and the defective gene of RBP.