In case 3C we detected two different metabolic diseases: Lysinuric protein intolerance (LPI) caused by mutations in SLC7A7 and Alpha-mannosidosis caused by mutations in MAN2B1. LPI is an autosomal recessive transport disorder of the dibasic amino acids lysine, arginine and ornithine in the renal tubules, intestinal epithelium, hepatocytes and fibroblasts [14]. Here, SLC7A7 is linked to lysinuric protein intolerance.