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Low or absent unconjugated estriol in pregnancy: an indicator for steroid sulfatase deficiency detectable by fluorescence in situ hybridization and biochemical analysis |
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| Authors: | Catherine D. Kashork V. Reid Sutton Jill S. Fonda Allen Deborah E. Schmidt Marisa L. Likhite Lorraine Potocki William E. O'Brien Lisa G. Shaffer |
| Affiliation: | 1. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA Kleberg Cytogenetics Laboratory, Baylor College of Medicine, Houston, TX, USA;2. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA Biochemical Genetics Laboratory, Baylor College of Medicine, Houston, TX, USA;3. The Center for Maternal Fetal Medicine and Reproductive Genetics, Rockville, MD, USA;4. Queens Medical Center, Honolulu, HI, USA;5. Partners Genetics Clinic, Massachusetts General Hospital, Boston, MA, USA;6. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA |
| Abstract: | It has been previously reported that a low or absent maternal serum unconjugated estriol (uE3) level is associated with placental steroid sulfatase (STS) deficiency. Here we report a correlation between patients who present with a very low or absent maternal serum uE3 and a deletion of the STS gene as assessed by fluorescence in situ hybridization (FISH). We studied nine prenatal cases that presented to the clinical laboratory with an abnormal triple screen, specifically low or absent maternal serum uE3 and a 46,XY karyotype. FISH analysis showed complete deletion of a probe containing the STS gene in six cases and one case had a partial deletion (reduced but not absent signal). The remaining two cases were not deleted for the STS probe. All mothers tested whose fetus showed a deletion were shown to be STS deletion carriers using FISH. Biochemical analysis was performed on 7/9 prenatal specimens. All fetuses deleted for the STS probe were also found to be deficient for STS by biochemical analysis of cultured amniotic fluid (5/5). Of the two fetuses not deleted for the STS probe, one was deficient for STS activity, while the other had a normal result. The abnormal result of enzyme deficiency by biochemical analysis in a non-deletion case likely represents a mutation in the STS gene, not detectable by this FISH assay. Postnatal FISH confirmation of the STS deletion was performed in 1/7 cases. Clinical follow-up was available for 4/9 cases following birth. Copyright © 2002 John Wiley & Sons, Ltd. |
| Keywords: | unconjugated estriol (uE3) steroid sulfatase (STS) contiguous gene deletion syndrome microdeletion ichthyosis laboratory diagnostics genetic testing |