Lysinuric protein intolerance is a disorder caused by the body's inability to digest and use certain protein building blocks (amino acids), namely lysine, arginine, and ornithine. Because the body cannot absorb these amino acids, which are found in many protein-rich foods, nausea and vomiting are typically experienced after ingesting protein.

Variants (also called mutations) in the SLC7A7 gene cause lysinuric protein intolerance. The SLC7A7 gene provides instructions for producing a protein called y+L amino acid transporter 1 (y+LAT-1), which is involved in transporting lysine, arginine, and ornithine between cells in the body. The transportation of amino acids from the small intestine and kidneys to the rest of the body is necessary for the body to be able to make and use proteins.

Lysinuric protein intolerance is estimated to occur in 1 in 50,000 newborns in Finland. This condition has also been found in numerous individuals in Japan and Italy. Outside these populations, this condition occurs less frequently, but the exact incidence is unknown.

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition.

Published Date: March 10, 2023
Published By: National Institutes of Health