Homozygous hypobetalipoproteinaemia and phenylketonuria.

Two patients, aged 0.1 and 2 years, with homozygous hypobetalipoproteinaemia, one with PKU in addition are described. The clinical evaluation showed no neurologic abnormalities. Treatment with a fat-reduced, protein and carbohydrate-enriched diet was combined with vitamin A and E supplementation, according to the suggestions for classical abetalipoproteinaemia. In the patient with PKU the protein intake was increased by using a phenylalanine-free, amino acid mixture. Only by this, were normal growth and weight gain achieved.