Lysinuric Protein Intolerance (LPI) usually occurs after weaning, and is characterized by repeated vomiting, diarrhea, and episodes of stupor, which may be followed by a comma after an intake of rich protein meal or poor feeding. Other causes are aversion to rich protein food, failure to thrive, enlargement of spleen and liver and hypotonia in the muscles. It occurs due to a mutation in the SLC7A7 gene. This gene is required for the transport of lysine, arginine and ornithine from the small intestine and kidneys to the rest of the body. The symptoms of this condition include poor growth, osteoporosis, renal involvement, pulmonary involvement, hemophagocytic macrophagic activation syndrome.
HOW IS LYSINURIC PROTEIN INTOLERANCE DIAGNOSED?
The diagnosis for LPI is based on biochemical findings and screening of known mutations.