Equine type estrogens produced by a pregnant woman carrying a Smith- Lemli-Opitz syndrome fetus

Cedric H.L. Shackleton, Esther Roitman, Lisa E. Kratz, Richard I. Kelley

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


The equine-type estriols 1,3,5 (10),7-estratetraene-3,16α, 17 β-triol (16α-hydroxy-17β-dihydroequilin) and 1,3,5(10),6,8-estrapentaene- 3,16α,17β-triol(16α-hydroxy-17β-dihydroequilenin) constituted over half of the estrogens excreted by a woman carrying a Smith-Lemli-Opitz syndrome (SLOS) affected fetus. The steroids were characterized by gas chromatography- mass spectrometry (GC/MS), and mass spectra of the dehydro estriols as trimethylsilyl ethers are illustrated. SLOS is associated with 7- dehydrocholesterol (7DHC), delta 7-reductase deficiency; the enzyme catalyzing the final step in cholesterol biosynthesis. Identification of these equine estrogens show that an estrogen biosynthetic pathway parallel to normal is functional in the feto-placental unit and uses 7DHC as precursor, therefore P450scc, P450c17, and 3βHSD and P450arom are all active on 7- dehydrometabolites. Patients with affected fetuses have low plasma estriol values (probably due to deficient production of the cholesterol precursor) and this is often a warning sign which instigates further evaluation for SLOS. The estriol deficiency is not quantitatively made up by the dehydrometabolites, and the combined excretion was found to be about one- third of the mean of gestational age matched controls. The importance of these findings lies in the potential value of dehydroestriol measurement for non-invasive diagnosis of SLOS at mid-gestation. Currently diagnosis relies on imaging, since SLOS is a malformation syndrome, and measurement of 7DHC levels in amniotic fluid and chorionic villus tissue.

Original languageEnglish (US)
Pages (from-to)1157-1159
Number of pages3
JournalJournal of Clinical Endocrinology and Metabolism
Issue number3
StatePublished - 1999

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Endocrinology
  • Clinical Biochemistry
  • Biochemistry, medical


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