SMITH-LEMLI-OPITZ-SYNDROME - A VARIABLE CLINICAL AND BIOCHEMICAL PHENOTYPE

We have reviewed all known UK cases of Smith-Lemli-Opitz syndrome. Amo ng 49 cases with proven 7-dehydrocholesterol reductase deficiency, hal f had been terminated or had died in infancy. The minimum incidence is 1 in 60000, The frequent occurrence of hypospadias may account for 71 % of recognised cases being male. Important common features which emer ged include short thumbs, severe photosensitivity, aggressive behaviou r, and atrioventricular septal defect. The typical facial appearance b ecomes less obvious with age and 20% of cases did not have 2/3 toe syn dactyly. Biochemical measurements of serum 7-dehydrocholesterol did no t correlate with clinical severity.