Lysinuric protein intolerance (LPI) is an inherited disorder that affects the body's ability to utilize certain building blocks of proteins. This condition usually appears after an infant is weaned and receives greater amount of protein from solid foods. Affected infants may have recurrent vomiting and diarrhea, nausea after a protein-rich meal, poor feeding, aversion to protein-rich food, enlarged liver and spleen, and muscular weakness. Overtime they may develop problems such as short stature, brittle bones, dysfunction of the lungs, impaired immune system , and kidney disease, which may be life threatening. LPI may lead to elevated ammonia levels in the blood, which may cause coma and intellectual disability. Treatment of LPI involves long term restriction of protein in diet and administration of arginine chloride and nitrogen scavenger drugs. LPI is caused by pathogenic variants in the SLC7A7 gene.