Abstract
The Smith-Lemli-Opitz syndrome (SLOS; also known as "RSH syndrome" [MIM 270400]) is an autosomal recessive multiple malformation syndrome due to a defect in cholesterol biosynthesis. Children with SLOS have elevated serum 7-dehydrocholesterol (7-DHC) levels and typically have low serum cholesterol levels. On the basis of this biochemical abnormality, it has been proposed that mutations in the human sterol Delta7-reductase (7-DHC reductase; E.C.1.3.1.21) gene cause SLOS. However, one could also propose a defect in a gene that encodes a protein necessary for either the expression or normal function of sterol Delta7-reductase. We cloned cDNA encoding a human sterol Delta7-reductase (DHCR7) on the basis of its homology with the sterol Delta7-reductase from Arabidopsis thaliana, and we confirmed the enzymatic function of the human gene product by expression in SLOS fibroblasts. SLOS fibroblasts transfected with human sterol Delta7-reductase cDNA showed a significant reduction in 7-DHC levels, compared with those in SLOS fibroblasts transfected with the vector alone. Using radiation-hybrid mapping, we show that the DHCR7 gene is encoded at chromosome 11q12-13. To establish that defects in this gene cause SLOS, we sequenced cDNA clones from SLOS patients. In three unrelated patients we have identified four different mutant alleles. Our results demonstrate both that the cDNA that we have identified encodes the human sterol Delta7-reductase and that mutations in DHCR7 are responsible for at least some cases of SLOS.
Full Text
The Full Text of this article is available as a PDF (1.5 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Alley T. L., Gray B. A., Lee S. H., Scherer S. W., Tsui L. C., Tint G. S., Williams C. A., Zori R., Wallace M. R. Identification of a yeast artificial chromosome clone spanning a translocation breakpoint at 7q32.1 in a Smith-Lemli-Opitz syndrome patient. Am J Hum Genet. 1995 Jun;56(6):1411–1416. [PMC free article] [PubMed] [Google Scholar]
- Altschul S. F., Gish W., Miller W., Myers E. W., Lipman D. J. Basic local alignment search tool. J Mol Biol. 1990 Oct 5;215(3):403–410. doi: 10.1016/S0022-2836(05)80360-2. [DOI] [PubMed] [Google Scholar]
- Altschul S. F., Madden T. L., Schäffer A. A., Zhang J., Zhang Z., Miller W., Lipman D. J. Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res. 1997 Sep 1;25(17):3389–3402. doi: 10.1093/nar/25.17.3389. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Berry R., Wilson H., Robinson J., Sandlin C., Tyson W., Campbell J., Porreco R., Manchester D. Apparent Smith-Lemli-Opitz syndrome and Miller-Dieker syndrome in a family with segregating translocation t(7;17)(q34;p13.1). Am J Med Genet. 1989 Nov;34(3):358–365. doi: 10.1002/ajmg.1320340312. [DOI] [PubMed] [Google Scholar]
- Bialer M. G., Penchaszadeh V. B., Kahn E., Libes R., Krigsman G., Lesser M. L. Female external genitalia and müllerian duct derivatives in a 46,XY infant with the smith-lemli-Opitz syndrome. Am J Med Genet. 1987 Nov;28(3):723–731. doi: 10.1002/ajmg.1320280320. [DOI] [PubMed] [Google Scholar]
- Chiang C., Litingtung Y., Lee E., Young K. E., Corden J. L., Westphal H., Beachy P. A. Cyclopia and defective axial patterning in mice lacking Sonic hedgehog gene function. Nature. 1996 Oct 3;383(6599):407–413. doi: 10.1038/383407a0. [DOI] [PubMed] [Google Scholar]
- Cunniff C., Kratz L. E., Moser A., Natowicz M. R., Kelley R. I. Clinical and biochemical spectrum of patients with RSH/Smith-Lemli-Opitz syndrome and abnormal cholesterol metabolism. Am J Med Genet. 1997 Jan 31;68(3):263–269. [PubMed] [Google Scholar]
- Curry C. J., Carey J. C., Holland J. S., Chopra D., Fineman R., Golabi M., Sherman S., Pagon R. A., Allanson J., Shulman S. Smith-Lemli-Opitz syndrome-type II: multiple congenital anomalies with male pseudohermaphroditism and frequent early lethality. Am J Med Genet. 1987 Jan;26(1):45–57. doi: 10.1002/ajmg.1320260110. [DOI] [PubMed] [Google Scholar]
- Dehart D. B., Lanoue L., Tint G. S., Sulik K. K. Pathogenesis of malformations in a rodent model for Smith-Lemli-Opitz syndrome. Am J Med Genet. 1997 Jan 31;68(3):328–337. doi: 10.1002/(sici)1096-8628(19970131)68:3<328::aid-ajmg15>3.0.co;2-v. [DOI] [PubMed] [Google Scholar]
- FOLCH J., LEES M., SLOANE STANLEY G. H. A simple method for the isolation and purification of total lipides from animal tissues. J Biol Chem. 1957 May;226(1):497–509. [PubMed] [Google Scholar]
- Irons M., Elias E. R., Salen G., Tint G. S., Batta A. K. Defective cholesterol biosynthesis in Smith-Lemli-Opitz syndrome. Lancet. 1993 May 29;341(8857):1414–1414. doi: 10.1016/0140-6736(93)90983-n. [DOI] [PubMed] [Google Scholar]
- Kelley R. I. Diagnosis of Smith-Lemli-Opitz syndrome by gas chromatography/mass spectrometry of 7-dehydrocholesterol in plasma, amniotic fluid and cultured skin fibroblasts. Clin Chim Acta. 1995 Apr 30;236(1):45–58. doi: 10.1016/0009-8981(95)06038-4. [DOI] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Lecain E., Chenivesse X., Spagnoli R., Pompon D. Cloning by metabolic interference in yeast and enzymatic characterization of Arabidopsis thaliana sterol delta 7-reductase. J Biol Chem. 1996 May 3;271(18):10866–10873. doi: 10.1074/jbc.271.18.10866. [DOI] [PubMed] [Google Scholar]
- Lei K. J., Gluzman Y., Pan C. J., Chou J. Y. Immortalization of virus-free human placental cells that express tissue-specific functions. Mol Endocrinol. 1992 May;6(5):703–712. doi: 10.1210/mend.6.5.1318503. [DOI] [PubMed] [Google Scholar]
- Lin D. S., Connor W. E., Wolf D. P., Neuringer M., Hachey D. L. Unique lipids of primate spermatozoa: desmosterol and docosahexaenoic acid. J Lipid Res. 1993 Mar;34(3):491–499. [PubMed] [Google Scholar]
- Moebius F. F., Fitzky B. U., Lee J. N., Paik Y. K., Glossmann H. Molecular cloning and expression of the human delta7-sterol reductase. Proc Natl Acad Sci U S A. 1998 Feb 17;95(4):1899–1902. doi: 10.1073/pnas.95.4.1899. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Natowicz M. R., Evans J. E. Abnormal bile acids in the Smith-Lemli-Opitz syndrome. Am J Med Genet. 1994 May 1;50(4):364–367. doi: 10.1002/ajmg.1320500413. [DOI] [PubMed] [Google Scholar]
- Porter J. A., Ekker S. C., Park W. J., von Kessler D. P., Young K. E., Chen C. H., Ma Y., Woods A. S., Cotter R. J., Koonin E. V. Hedgehog patterning activity: role of a lipophilic modification mediated by the carboxy-terminal autoprocessing domain. Cell. 1996 Jul 12;86(1):21–34. doi: 10.1016/s0092-8674(00)80074-4. [DOI] [PubMed] [Google Scholar]
- Porter J. A., Young K. E., Beachy P. A. Cholesterol modification of hedgehog signaling proteins in animal development. Science. 1996 Oct 11;274(5285):255–259. doi: 10.1126/science.274.5285.255. [DOI] [PubMed] [Google Scholar]
- Roux C., Dupuis R., Horvath C., Talbot J. N. Teratogenic effect of an inhibitor of cholesterol synthesis (AY 9944) in rats: correlation with maternal cholesterolemia. J Nutr. 1980 Nov;110(11):2310–2312. doi: 10.1093/jn/110.11.2310. [DOI] [PubMed] [Google Scholar]
- SMITH D. W., LEMLI L., OPITZ J. M. A NEWLY RECOGNIZED SYNDROME OF MULTIPLE CONGENITAL ANOMALIES. J Pediatr. 1964 Feb;64:210–217. doi: 10.1016/s0022-3476(64)80264-x. [DOI] [PubMed] [Google Scholar]
- Scherer S. W., Soder S., Duvoisin R. M., Huizenga J. J., Tsui L. C. The human metabotropic glutamate receptor 8 (GRM8) gene: a disproportionately large gene located at 7q31.3-q32.1. Genomics. 1997 Sep 1;44(2):232–236. doi: 10.1006/geno.1997.4842. [DOI] [PubMed] [Google Scholar]
- Shefer S., Salen G., Batta A. K., Honda A., Tint G. S., Irons M., Elias E. R., Chen T. C., Holick M. F. Markedly inhibited 7-dehydrocholesterol-delta 7-reductase activity in liver microsomes from Smith-Lemli-Opitz homozygotes. J Clin Invest. 1995 Oct;96(4):1779–1785. doi: 10.1172/JCI118223. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tint G. S., Irons M., Elias E. R., Batta A. K., Frieden R., Chen T. S., Salen G. Defective cholesterol biosynthesis associated with the Smith-Lemli-Opitz syndrome. N Engl J Med. 1994 Jan 13;330(2):107–113. doi: 10.1056/NEJM199401133300205. [DOI] [PubMed] [Google Scholar]
- Tint G. S., Salen G., Batta A. K., Shefer S., Irons M., Elias E. R., Abuelo D. N., Johnson V. P., Lambert M., Lutz R. Correlation of severity and outcome with plasma sterol levels in variants of the Smith-Lemli-Opitz syndrome. J Pediatr. 1995 Jul;127(1):82–87. doi: 10.1016/s0022-3476(95)70261-x. [DOI] [PubMed] [Google Scholar]