Lysinuric protein intolerance in a family of Mexican ancestry with a novel SLC7A7 gene deletion. Case report and review of the literature.

Lysinuric protein intolerance (LPI) is a rare autosomal recessive disorder caused by mutations in the SLC7A7 located on the chromosome 14q11.2. LPI is most prevalent in Finland (1:50,000), Northern Japan (1:60,000) and Italy. Cases have also been reported in Spain and the United States. Here we report two siblings of Mexican descent. The older child was diagnosed at the age of three with severe chronic respiratory insufficiency leading to her demise. In contrast, the younger child was diagnosed soon after birth and dietary therapy has led to a stable life. Genetic analysis revealed a previously unreported deletion in the SLC7A7 gene. Additional research is needed to clarify the role of lysine in the pathophysiology of pulmonary proteinosis and herpes infections.