This condition  involves an inborn error of amino acid metabolism as well as niacin deficiency.

Cause

Poor nutrition, exposure to sunlight, psychological stress.

Symptoms

Mild mental retardation, gastrointestinal problems ,skin problems, coordination impairment, visionproblems, , and central nervous system abnormalities

Treatment

Take a high-protein diet , physical and chemical protection from sunlight: avoid excessive exposure to sunlight, wear protective clothing.