MSH: An inherited disorder due to defective reabsorption of CYSTINE and other BASIC AMINO ACIDS by the PROXIMAL RENAL TUBULES. This form of aminoaciduria is characterized by the abnormally high urinary levels of cystine; LYSINE; ARGININE; and ORNITHINE. Mutations involve the amino acid transport protein gene SLC3A1.,CSP: inherited abnormality of renal tubular transport of dibasic amino acids leading to massive urinary excretion of cystine, lysine, arginine, and ornithine.,NCI: An autosomal recessive inherited metabolic disorder caused by mutations in the SLC3A1 and SLC7A9 genes. It is characterized by deficient re-absorption of cystine in the proximal tubules of the kidney. It results in the formation of stones in the kidney, ureter, and urinary bladder.