Sterol-4-alpha-carboxylate 3-dehydrogenase, decarboxylating is an enzyme that in humans is encoded by the NSDHL gene.

The protein encoded by this gene is localized in the endoplasmic reticulum and is involved in cholesterol biosynthesis. Mutations in this gene are associated with CHILD syndrome, which is a X-linked dominant disorder of lipid metabolism with disturbed cholesterol biosynthesis, and typically lethal in males. Alternatively spliced transcript variants with differing 5' UTR have been found for this gene. [provided by RefSeq].