Genetic Testing Company | The DNA Diagnostic Experts | GeneDx

In observance of the holidays, GeneDx will be closed for business on Thursday, December 25, 2014 and on Thursday, January 1, 2015. We will be unable to receive and process specimens. FedEx and UPS will also not be in operation. Except for the aforementioned dates, GeneDx will operate on our normal schedule (Monday-Saturday), including December 24th and December 31st.  If you have any questions or inquiries, please call us at 301-519-2100 or email us at

Prenatal DHCR7 Gene Sequencing



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:
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


CPT Codes:
81405x1, 81265x1, 88235x1
New York Approved:
ABN Required:
Billing Information:
View Prenatal Billing Policy
ICD Codes:
  • 655.83: Other known or suspected fetal abnormality, not elsewhere classified
  • 796.5: Abnormal finding on antenatal screening
  • 655.23: Hereditary disease in family possibly affecting fetus
* For price inquiries please email


  1. Witsch-Baumgartner et al., (2000) Am J Hum Genet 66:402-412
  2. Correa-Cerro et al., (2005) Mol Gen Metab 84:112-26;
  3. Yu, H. and Patel, S.B., (2005) Clin Genet 68:383-91
  4. Goldenberg A, et al., Am J Med Genet A. 2004; 124: 423–6.
  5. Rossiter et al., (1995) Am J Med Genet 56:272-5.
  6. Irons, M. (Updated [Oct. 24, 2007]) Smith-Lemli-Opitz Syndrome In: GeneReviews at Genetests: Medical Genetics Information Resource (database online). Copyright, University of Washington, Seattle. 1997- 2010. Available at

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