Preferred Sample Type


Suitable Specimen Types

  • Serum
  • Li Hep Plasma
2 mL blood

Specimen Transport

First Class Post to reference laboratory

Sample Processing in Laboratory

No special requirements for transporting sample to the laboratory

Sample Preparation

Lithium heparin plasma

Turnaround Time

3 weeks

Sample Stability

store frozen prior to shipment to referral laboratory


General Information

7-dehydrocholesterol is a precursor of cholesterol biosynthesis. Elevated levels of 7-dehydrocholesterol and low levels of cholesterol are found in patients with Smith Lemli Opitz (SLO) syndrome. This is an autosomal recessive disorder characterised by dysmorphic features with abnormalities of limbs and genitalia. The primary defect in SLO is presumed to be due to a deficiency of delta-7-dehydrocholesterol reductase. Measurement of 7-dehydrocholesterol is particularly important in patients suspected of having SLO when cholesterol levels are low-normal, as high levels of 7-dehydrocholesterol may interfere with cholesterol assays.

Patient Preparation




Reference Range

Provided by Reference Laboratory


  • EQA Scheme?: Yes
  • EQA Status:


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HTA licence number is 12366

Protection of Personal Information – Laboratory Medicine comply with the Trust Data Protection Policy and have procedures in place to allow the Directorate and it’s employees to comply with the Data Protection Act 1998 and associated best practice and guidance.

The Trust Laboratories at Heartlands Hospital, Good Hope Hospital and Solihull Hospital were awarded UKAS (United Kingdom Accreditation Service) accreditation to the internationally recognised ISO 15189 standard in May 2015. For a list of accredited tests and other information please visit the test database
Tests not appearing on this scope are either under consideration or in the process of accreditation and so currently remain outside of our scope of accreditation. However, these tests have been validated to the same high standard as accredited tests and are performed by the same trained and competent staff.

For further information contact Louise Fallon, Quality Manager, 0121 424 1235