Rickets as an unusual initial presentation of abetalipoproteinemia and hypobetalipoproteinemia.

OBJECTIVE

Description of rickets as an unexpected initial manifestation in two children with abetalipoproteinemia and hypobetalipoproteinemia, and elucidation of its pathophysiology in these conditions.

METHODOLOGY: Two infants aged two and six months with abetalipoproteinemia and hypobetalipoproteinemia respectively had clinical rickets at presentation, confirmed radiologically and biochemically. Vitamin D intake and serum levels were measured and other causes of rickets were looked for.

RESULTS

Vitamin D intake and laboratory studies levels were suggestive of rickets due to calcium deficiency instead of vitamin D deficiency. Healing of rickets occurred with dietary treatment of the malabsorption, without any dietary calcium or significant vitamin D supplementation.

CONCLUSION

Steatorrhea-induced calcium malabsorption seems to be the most likely cause of rickets in this entity.