title: Sterol profiles in plasma and erythrocyte membranes in patients with Smith-Lemli-Opitz syndrome: a six-year experience.
abstract: BACKGROUND
  This study reports our experience over the last six years in the diagnosis of Smith-Lemli-Opitz syndrome and other inborn errors of cholesterol biosynthesis.
  
  
  METHODS
  Gas chromatography/mass spectrometry was used to obtain sterol profiles in plasma and erythrocyte membranes of suspected patients.
  
  
  RESULTS
  Plasma sterol reference values calculated in unaffected subjects (n=276) were in agreement with those previously reported. Among patients investigated from 2005 to 2010, we report 16 patients affected by Smith-Lemli-Opitz syndrome, three of whom represent new cases and 13 of whom were follow-up patients. In this period we also identified a new case of chondrodysplasia punctata 2 X-linked. The estimated incidence obtained for Smith-Lemli-Opitz syndrome was 1:93 suspected patients (1.08%). We also studied the effect of storage on the dehydrocholesterols/cholesterol ratio in plasma and erythrocyte membranes of patients affected by Smith-Lemli-Opitz syndrome stored at -20°C for up to 22 and 20 months, respectively. A significant negative linear correlation between storage time and the dehydrocholesterols/cholesterol ratio was identified in both plasma and erythrocyte membranes. The decrease in the dehydrocholesterols/cholesterol ratio in erythrocyte membranes was at least two-fold higher than in plasma.
  
  
  CONCLUSIONS
  The results of this study may be helpful for diagnosis and interpretation of data in patients with findings suggestive of a cholesterol biosynthesis defect.
authors.affiliation: Department of Biochemistry and Medical Biotechnologies, University Federico II of Naples, Naples, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Corso
authors.forename: Monica
authors.initials: M
authors.lastname: Gelzo
authors.forename: Rosalba
authors.initials: R
authors.lastname: Barone
authors.forename: Stefano
authors.initials: S
authors.lastname: Clericuzio
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Pianese
authors.forename: Angela
authors.initials: A
authors.lastname: Nappi
authors.forename: Antonio
authors.initials: A
authors.lastname: Dello Russo
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002784:Cholesterol / Q000032:analysis* / Q000097:blood; D002806:Chondrodysplasia Punctata / Q000097:blood / Q000175:diagnosis; D003684:Dehydrocholesterols / Q000032:analysis* / Q000097:blood; D004910:Erythrocyte Membrane / Q000737:chemistry*; D005260:Female; D005500:Follow-Up Studies; D008401:Gas Chromatography-Mass Spectrometry; D040181:Genetic Diseases, X-Linked / Q000097:blood / Q000175:diagnosis; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D019082:Smith-Lemli-Opitz Syndrome / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D055815:Young Adult
chemical_list: D003684:Dehydrocholesterols; D002784:Cholesterol