Dibasic Protein Intolerance

Dibasic protein intolerance is a rare inherited disorder caused by a defect in membrane transport of dibasic amino acids. It is caused by a mutation in the SLC7A7 gene. It is a multisystemic metabolic disease. Its management is made difficult by the complexity of its pathophysiology. The median age of onset was 9 months. The median age at diagnosis was 21 months. Growth retardation (n=7) and hepatosplenomegaly (n=6) were almost constant signs of the disease, followed by protein aversion (n=5), pallor (n=5) and neurological signs (n=4). Ammonia was elevated in 6 patients. Amino acid chromatography supported the diagnosis in two patients. Molecular biology revealed the del TTCT 1471 mutation in 5 patients. A low-protein diet and citrulline supplementation were prescribed in all patients. Complications of the disease were frequent: growth retardation was noted in all patients.