Friday 14 November 2003
Cholesterol is synthesized from lanosterol, the first sterol in the cholesterol synthesis pathway, via a series of enzymatic reactions.
These include the demethylation at C4α, C4β, and C14, which converts the C30 molecule lanosterol to C27 cholesterol; isomerization of the Δ8(9) double bond to a Δ7 double bond; desaturation to form a Δ5 double bond; and finally, reduction of Δ14, Δ24, and Δ7 double bonds.
Analyses of human and murine syndromes resulting from cholesterol synthetic defects have helped illuminate both the normal functions of cholesterol and a range of normal and teratogenic functions of the various precursor sterols that accumulate in these disorders.
Pathology (Anomalies of cholesterol biosynthesis)
Smith-Lemli-Opitz syndrome (SLOS) (MIM.270400)
X-linked dominant chondrodysplasia punctata type 2
CHILD syndrome (MIM.308050)
Greenberg dysplasia (MIM.215140)
Antley-Bixler syndrome (MIM.207410) (craniosynostosis syndrome)
deficiency of 3beta-hydroxysteroid-delta5-desaturase (lathosterolosis) by mutations in the 3beta-hydroxysteroid-Delta(5)-desaturase (SC5D) (12189593)