Loss-of-function mutation in carotenoid 15,15'-monooxygenase identified in a patient with hypercarotenemia and hypovitaminosis A.

The enzyme carotenoid 15,15'-monooxygenase (CMO1) catalyzes the first step in the conversion of dietary provitamin A carotenoids to vitamin A in the small intestine. Plant carotenoids are an important dietary source of vitamin A (retinol) and the sole source of vitamin A for vegetarians. Vitamin A is essential for normal embryonic development as well as normal physiological functions in children and adults.

Subcutaneous xanthomatosis.

A patient with multiple subcutaneous xanthomata in whom there were only minor abnormalities of the fasting serum lipid profile is described. To our knowledge, this is only the second published case of subcutaneous xanthomatosis.