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chapter 19

Lipids li: Phospholipids, Glycosphingolipids, and Cholesterol

I

1

I

i

NADPH

,>-NADP+

FIGURE 19-16

A partial pathway for the conversion of lanosterol to cholesterol. The complete process consists of 19 steps. The

C

2 4

= C

25

double bond can be reduced by 3/1-hydroxylsteroid- A24-reductase at several steps along the pathway

(indicated by 1), and deficiency of this enzyme leads to accumulation of desmosterol. Deficiency of enzyme 2 and

enzyme 3 results in CDPX2 and SLO syndromes, respectively (see text).