Genetic Testing Company | The DNA Diagnostic Experts | GeneDx

In observance of Thanksgiving, GeneDx will be closed and will not accept specimens on Thursday, November 26, 2015. We will accept specimens but operate on a modified schedule on Friday, November 27, 2015.  We will resume our normal schedule on Saturday, November 28, 2015.  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
New York Approved:
ABN Required:
Billing Information:
View Prenatal Billing Policy
* For ICD9 to ICD10 conversion please follow this link
ICD-9 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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