Patent ID: 8158435

Claim:
A method of diagnosing or screening an individual for conditions associated with altered sterols, comprising: providing a biological sample containing sterols, the sample obtained from the individual; derivatizing the sterols by reacting the sterols with a derivatizing reagent; detecting the derivatized sterols using tandem mass spectrometry with electrospray ionization amenable to high-throughput screening to quantify the sterols in the biological sample using deuterated internal standard or to determine a discriminatory metabolic sterol ratio; and comparing the quantified sterols or metabolic sterol ratio in the biological sample with values of sterols for individuals unaffected with a condition associated with altered sterols to determine whether the sterols in the biological sample are elevated compared to the values of sterols for the individuals unaffected and thus indicative of one or more conditions associated with altered sterols, wherein the conditions associated with altered sterols comprise Smith-Lemli-Opitz syndrome, familial hypercholesterolaemia, and cerebrotendinous xanthomatosis, and wherein the comparing comprises comparing data for the quantified sterols or metabolic sterol ratio in the sample with values of sterols for the unaffected individuals to determine whether the quantified sterols or metabolic sterol ratio in the sample are indicative independently of each of the conditions associated with altered sterols.