Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2005 Apr;19(3):223-30.
doi: 10.1002/bmc.439.

Determination of urinary S-sulphocysteine, xanthine and hypoxanthine by liquid chromatography-electrospray tandem mass spectrometry

Mohamed S Rashed  1 , Amal A A Saadallah, Zuhair Rahbeeni, Wafaa Eyaid, Mohamed Z Seidahmed, Saad Al-Shahwan, Mustafa A M Salih, Mohammad E Osman, Mohamed Al-Amoudi, Lujane Al-Ahaidib, Minnie Jacob
Affiliations

Determination of urinary S-sulphocysteine, xanthine and hypoxanthine by liquid chromatography-electrospray tandem mass spectrometry

Mohamed S Rashed et al. Biomed Chromatogr. 2005 Apr.

Abstract

Molybdenum cofactor and isolated sulphite oxidase deficiencies are two related rare autosomal recessive diseases characterized by severe neurological abnormalities, dislocated lens and mental retardation. Determination of three biochemical markers S-sulphocysteine (SSC), xanthine (XAN) and hypoxanthine (HXAN) in urine is essential for a definitive diagnosis and identification of the exact defect. We developed a rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of SSC, XAN and HXAN in urine. The analysis was carried out in the negative-ion selected-reaction monitoring mode. The turnaround time for the assay was 7 min. Linear calibration curves for the three biomarkers were obtained in the range of 12-480 micromol/L. The intra- and inter-day assay variations were <2.5%. Mean recoveries of SSC, XAN and HXAN added to urine at two significantly different concentrations were in the range 94.3-107.3%. At a normal SSC urine excretion value of 3.2 micromol/mmol creatinine, the signal-to-noise ratio was 337:1. This stable isotope dilution LC-MS/MS method is specific, rapid and simple, and provides definitive diagnosis for molybdenum cofactor and isolated sulphite oxidase deficiencies in very small volumes of urine. We have identified seven new cases of isolated sulphite oxidase deficiency from four Saudi families and one Sudanese family.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types