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Prenatal Smith-Lemli-Opitz Syndrome




  • Smith-Lemli-Opitz Syndrome

Clinical Utility

  • Full gene sequencing for fetuses with increased 7-DHC levels measured in amniotic fluid or CVS tissue
  • In the case of ultrasound findings and/or abnormal maternal serum screening suggestive of SLOS and no family history, prenatal measurement of 7-DHC levels is recommended as a first step
  • Mutation-specific testing for fetuses with a family history of two known DHR7 mutations

Lab Method

  • Capillary Sequencing

Test Code


CPT Codes*


ABN Required


Turnaround Time**

2-3 weeks

Preferred Specimen

20 mL Amniotic Fluid

Alternative Specimen

20 mg CVS | 2 T25 flasks of cultured amniocytes | 2 T25 flasks of cultured chorionic villi | 3 Ug DNA Concentration

*The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

**Reporting times are typical and begin once the sample(s) are received at the GeneDx laboratory, but could be extended in situations outside GeneDx’s reasonable control.