Cystinuria Profile, Quantitative 24 Hour Urine | Cleveland Clinic Laboratories

Cystinuria Profile, Quantitative 24 Hour Urine Print

Test Mnemonic

UCYS24

CPT Codes

82136 - QTY (1)

Includes

Cystine
Lysine
Ornithine
Arginine

Performing Laboratory

Mayo Clinic Dpt of Lab Med & Pathology

Specimen Requirements

Volume	Type	Container	Collect Temperature	Transport Temperature	Special Instructions
5 mL	Urine, 24-hour (well-mixed)	Clean container	Refrigerate during collection.	Frozen

Minimum Specimen Requirements

Volume	Type	Container	Collect Temperature	Transport Temperature	Special Instructions
1 mL

Stability

Environmental Condition	Description
Frozen	70 days
Refrigerated	14 days

Days Performed

Mon - Fri

Turnaround Time

5 - 8 days

Methodology

Name	Description
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reference Range

Arginine
Sex	Age From	Age To	Type	Range	Range Unit
	3 Years	15 Years	Normal	10-25	mcmol/24 hours
	16 Years	99 Years	Normal	13-64	mcmol/24 hours
Cystine
Sex	Age From	Age To	Type	Range	Range Unit
	3 Years	15 Years	Normal	11-53	mcmol/24 hours
	16 Years	99 Years	Normal	28-115	mcmol/24 hours
Lysine
Sex	Age From	Age To	Type	Range	Range Unit
	3 Years	15 Years	Normal	19-140	mcmol/24 hours
	16 Years	99 Years	Normal	32-290	mcmol/24 hours
Ornithine
Sex	Age From	Age To	Type	Range	Range Unit
	3 Years	15 Years	Normal	3-16	mcmol/24 hours
	16 Years	99 Years	Normal	5-70	mcmol/24 hours

Special Info

Collect before intravenous pyelogram.

Clinical Info

Cystinuria is an inborn error of metabolism resulting from poor absorption and reabsorption of the amino acid cystine in the intestine and in the kidney. This leads to an accumulation of poorly soluble cystine in the urine and results in the production of kidney stones (urolithiasis). Symptoms may include acute episodes of abdominal or lower back pain, presence of blood in the urine (hematuria), and recurrent episodes of kidney stones may result in frequent urinary tract infections, which may ultimately result in renal insufficiency. The combined incidence of cystinuria has been estimated to be 1 in 7,000. Cystinuria can be classified into 3 subtypes based on the excretion of amino acids in the urine of heterozygotes (parents or children of affected individuals). Heterozygotes of type I excrete normal amounts of cystine, while those with types II and III present with slight to moderate excretion of cystine and other amino acids (lysine, arginine, and ornithine). All 3 subtypes are caused by mutations in only 2 genes, SLC3A1 on chromosome 2p and SLC7A9 on chromosome 19q. A new classification system has been proposed to distinguish the various forms of cystinuria: type A, due to mutations in the SLC3A1 gene; type B, due to mutations in the SLC7A9 gene; and type AB, due to 1 mutation in each SLC3A1 and SLC7A9.