Cholesterol treatment forever? The first Scandinavian trial of cholesterol supplementation in the cholesterol-synthesis defect Smith-Lemli-Opitz syndrome.

OBJECTIVES

To investigate if exogenous cholesterol affects sterol turnover in the cholesterol-synthesis defect Smith-Lemli-Opitz syndrome (SLOS) and if clinical effects justify long-time supplementation. The SLOS is caused by a deficiency of the enzyme 7-dehydrocholesterol-7-reductase with markedly reduced cholesterol levels and greatly increased levels of 7-dehydrocholesterol (7-DHC).

DESIGN

Treatment with dietary cholesterol in patients with SLOS in a case series study.

SETTING

All biochemical analyses were performed in one laboratory. The clinical follow-up was carried out by one of the authors (LS), a paediatric neurologist.

SUBJECTS

Seven patients with biochemically verified SLOS have been diagnosed in Sweden and all of them are included in the study.

INTERVENTIONS

Six patients were treated for 0.5-6 years orally with cholesterol and the bile acid taurocholate and one patient was supplemented with cholesterol only.

MAIN OUTCOME MEASURES

In addition to cholesterol, 7- and 8-DHC, lathosterol was used as a marker of endogenous cholesterol synthesis and the patients were followed clinically. Nerve conduction velocities (NCV) were measured before treatment in all patients and a UVA-light test was performed in one of them.

RESULTS

Lathosterol was initially increased by cholesterol supply in subjects with very low cholesterol levels with subsequent rise of 7- and 8-DHC. Photosensitivity clinically improved in all, verified by UVA-light testing in one. Progressive polyneuropathy improved, whilst stationary forms did not.

CONCLUSION

Dietary cholesterol can up-regulate sterol turnover in severely affected patients. Although some specific features are treatable and verifiable by objective methods, data supporting life-long treatment dietary cholesterol in all SLO patients are still lacking.