Lysinuric protein intolerance with novel mutations in solute carrier family 7A member 7 in a Chinese family

Introduction:Lysinuric protein intolerance(LPI)is a rare genetic disorder caused by mutations in the solute carrier family 7A member 7(SLC7A7)gene.Case presentation:We presented two siblings with LPI,carrying novel mutations of c.776delT(p.L259Rfs*18)and c.155G>T(p.G52V)in SLC7A7.The younger sibling,preferring protein-rich foods,showed severe symptoms,including alveolar proteinosis,macrophage activation syndrome,severe diarrhea,and disturbance of consciousness with involuntary movements.In contrast,the elder sibling only had mild symptoms,likely due to aversion to protein-rich food since toddler age.Conclusion:LPI is a congenital genetic metabolic disease with multisystem involvement.Initiating appropriate protein-restricted diet therapy as soon as possible could help prevent the progression of LPI.