[Biochemical diagnosis of Smith-Lemli-Opitz syndrome in a patient with congenital adrenal hyperplasia].

AIM

Smith-Lemli-Opitz syndrome is an autosomal recessive disorder caused by 7 dehydrocholesterol D7 reductase deficiency that leads to serum cholesterol deficiency and accumulation of the cholesterol precursor, 7 dehydrocholesterol. We report a three-month-old boy with congenital adrenal hyperplasia and clinical diagnosis of this syndrome. This study was undertaken to confirm biochemically the clinical diagnosis of Smith-Lemli-Opitz syndrome.

METHODS

Serum 7 dehydrocholesterol was determined in serum by ultraviolet spectroscopy (qualitatively) using a recently described simple and rapid method, and by gas chromatography (quantitatively).

RESULTS

The ultraviolet spectroscopy assay detected serum 7 dehydrocholesterol. This result was confirmed by gas chromatography. Furthermore, the patient showed very low total cholesterol.

CONCLUSIONS

The association between Smith-Lemli-Opitz syndrome and congenital adrenal hyperplasia has been reported in only a few cases. Our results suggest that clinical diagnosis of Smith-Lemli-Opitz syndrome can be biochemically confirmed by qualitative measurement of 7 dehydrocholesterol using ultraviolet spectroscopy.