Molybdenum Cofactor Deficiency: Metabolic Link Between Taurine and S-Sulfocysteine - Advances in Experimental Medicine and Biology - page 14

Fig. 2.1 HPLC analysis of hypotaurine, taurine, and SSC in a control individual ( a ) and an MoCD
patient ( b ). An overlay of both chromatograms—control individual ( solid line ) and MoCD patient
( dashed line )—highlighting hypotaurine and taurine peaks is shown in ( c ). SSC, hypotaurine, and
taurine are highlighted in panels ( a ) and ( b ) by arrows

sample derived from an MoCD patient showed—in addition to an accumulated SSC
peak—a clear accumulation of both hypotaurine and taurine (Fig. 2.1b ). Comparison
of the chromatograms derived from a healthy control sample (Fig. 2.1c , solid line)
and an MoCD patient sample (Fig. 2.1c , dashed line) revealed a tenfold increase in
the urinary excretion levels of hypotaurine and taurine in the MoCD patient
(Fig. 2.1c ).

2.3.2 Determination of Taurine Excretion Levels

in Healthy and MoCD Patients

After confirming that hypotaurine and taurine excretion levels are up-regulated in
an MoCD patient, the method was applied to the analysis of nine urine samples
derived from MoCD patients as well as urine samples from control individuals. As
expected, the SSC values were very low in control samples (1-9 mmol/mol creati-
nine), while hypotaurine and taurine levels ranged from 10 to 70 (median 21) and
30 to 100 (median 67) mmol/mol creatinine, respectively (Fig. 2.2a ). In contrast,
samples derived from MoCD patients showed, in addition to SSC accumulation