The Turkish Journal of Pediatrics
2010 , Vol 52 , Num 1
Abetalipoproteinemia in an infant with severe clinical phenotype and a novel mutation
1Unit of Pediatric Gastroenterology, Hepatology and Nutrition, Hacettepe University Faculty of Medicine, Ankara, Turkey,
and 2Department of Biomedical Sciences, University of Modena and Reggio Emilia, Modena, Italy
Abetalipoproteinemia (ABL) is a rare autosomal disorder characterized by
extremely low levels of plasma lipids and apolipoprotein B (apoB) with a
variable phenotype. Mutations in the MTP gene encoding the microsomal
triglyceride transfer protein (MTP) cause the disease. A five-month-old
boy, born from consanguineous parents, with chronic diarrhea and severe
malnutrition had extremely low plasma lipids and apoB levels suggesting the
diagnosis of ABL. He was not responsive to treatment with low-fat diet and
fat-soluble vitamins and died at 13 months of age with severe malnutrition.
Analysis of the MTP gene showed that he was homozygous for a two nucleotide
deletion in exon 4 (c.398-399delAA) expected to cause a frameshift in
the mRNA leading to a premature termination codon. The normolipidemic
proband’s parents were found to be heterozygous for the mutation. This
observation underscores that in some cases, ABL can be extremely severe
from early post-natal life and poorly responsive to treatment.
Keywords :
abetalipoproteinemia, MTP gene, infancy.