• Molecules and Cells
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• 제19권2호
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• pp.279-282
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• 2005

In mammals, 7-dehydrocholesterol reductase (Dhcr7) is the terminal enzyme in cholesterol biosynthesis. We previously reported that the Dhcr7 proximal promoter (-179 to +1), which contains CpG islands, is responsible for sterol-mediated expression of the rat gene. In the present study, we examined whether methylation of this region affects the transcriptional activity of the Dhcr7 gene. In vitro DNA methylation of the Dhcr7 promoter and luciferase-reporter assays showed that DNA methylation of the CpG islands suppressed transcription. Furthermore, treatment of the methylated Dhcr7 promoter with the demethylating agent, 5-aza-2'-deoxycytidine (5-Aza-CdR), reversed the suppression of promoter activity. These results indicate that methylation of the CpG islands is an important transcriptional regulatory mechanism in the Dhcr7 promoter.

• Clinical and Experimental Pediatrics
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• 제51권11호
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• pp.1236-1240
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• 2008

Smith-Lemli-Opitz 증후군은 콜레스테롤 합성 과정의 장애로 발생하는 상염색체 열성으로 유전되는 드문 질환으로 다양한 기형을 동반한다. 이는 DHCR7 유전자 변이로 인한 활성도 저하로 발생하는 질환으로 7DHC, 8DHC의 증가 및 체내 콜레스테롤의 감소에 따른 임상상을 특징으로 한다. 저자들은 국내에서 최초로 SLO 증후군을 유전자 분석을 통하여 진단하였기에 이를 문헌 고찰과 함께 보고하는 바이다.

• BMB Reports
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• 제30권5호
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• pp.370-377
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• 1997

A novel assay method is described for rapid quantitation of reaction rate of sterol ${\Delta}^7$-reductase (${\Delta}^7$-SR) which catalyzes reduction of the ${\Delta}^7$-double bond of sterols. Of six different organ tissues-liver, small intestine, brain, lung, kidney, and testis-. ${\Delta}^7$-SR activity was detected only in liver (2.30 nmol/min/mg protein) and testis (0.11 nmol/min/mg protein). Using a newly developed method which employs diet-induced enzyme proteins and ergosterol as substrate, we assessed both kinetics ($K_m=210\;{\mu}M$, $V_{max}=1.93\;nmol/min/mg$) and inhibition of the rat hepatic ${\Delta}^7$-SR against well-studied cholesterol lowering agents such as triparanol ($IC_{50}=16\;{\mu}M$). 3-$\beta$-[2-(diethylamino)ethoxy]androst-5-en-17-one (U18666A) ($IC_{50}=5.2\;{\mu}M$), and trans-1.4-bis(2-chlorobenzylaminomethyl)cyclohexane dihydrochloride (AY-9944) ($IC_{50}=0.25\;{\mu}M$). Of the three well-known AY-9944-sensitive cholesterogenic enzymes (i.e., ${\Delta}^7$-SR, sterol ${\Delta}^8$-isomerase, and sterol ${\Delta}^14$-reductase). ${\Delta}^7$-SR was found to be the most sensitive enzyme with a noncompetitive inhibition of this compound ($K_i=0.109\;{\mu}M$). Substrate specificity studies of the microsomal ${\Delta}^7$-SR indicate that the relative reaction rate for 7-dehydrocholesterol and ergosterol are 5.6-fold and 1.6-fold higher than that for lathosterol. ${\Delta}^7$-SR activity was also modulated by feeding rats a diet supplemented with 0.5% ergosterol (>2.6-fold) in addition to 5.0% cholestyramine plus 0.1% lovastatin ($\simeq$5.0-fold). Finally, microsomal ${\Delta}^7$-SR was solubilized by 1.5% 3-[3-(cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS) and enriched on PEG (0~10%) precipitation, which should be suitable for further purification of the enzyme.

• 대한유전성대사질환학회지
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• 제14권1호
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• pp.48-53
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• 2014

Smith-Lemli-Opitz syndrome (SLO) is a rare, autosomal recessive disease caused by an inborn error in cholesterol synthesis. Patients with this disease suffer from multiple malformations due to reduced activity of 7-dehydrocholesterol reductase (DHCR7), which increases 7-dehydrocholesterol (7DHC) and 8-dehydrocholesterol (8DHC) concentrations and decreases cholesterol concentration in body fluids and tissue. Here, we describe Korean siblings with SLO who were diagnosed recently, and performed a review of literature about Korean cases with SLO to date. Microcephaly and syndactyly of the second and third toes are the most common physical finding in SLOS patients. Other malformations including growth failure, cleft palate or bifid uvula, various heart malformation, genital ambiguity in males are also accompanied. Not all patients showed low levels of serum cholesterol, so DHCR7 mutation analysis can be helpful to confirmative diagnosis. Two mutations on p.R352 locus (p.R352W and p.R352Q) are commonly identified in Korean SLO patients. Although rare in Korea, SLO should be considered in the differential diagnosis of growth failure with intellectual disability, especially in patients with multiple congenital anomalies.

• Journal of Genetic Medicine
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• 제11권2호
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• pp.86-90
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• 2014

Smith-Lemli-Opitz syndrome (SLOS) is a rare autosomal recessive disorder caused by 7-dehydrocholesterol reductase deficiency. The characteristic clinical features are syndactyly of the second and third toes, facial dysmorphism, multiple malformations, and intellectual disability. Few cases of SLOS have been reported in Korea. We observed a male patient with SLOS who presented with typical facial features, undescended testes, microcephaly, bilateral syndactyly of the second and third toes, and cardiac defects, including patent ductus arteriosus and atrial septal defect. Mutation analysis of the DHCR7 gene identified compound heterozygous mutations of c.907G>A (p.Gly303Arg) and c.1055G>A (p.Arg352Gln). In a review of the literature, c.1054C>T (p.Arg352Trp) was the most common mutation reported in Far East Asian countries. This report describes the clinical features, biochemical data, molecular characteristics, and clinical outcome of a Korean patient with SLOS.

• 대한유전성대사질환학회지
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• 제14권1호
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• pp.60-65
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• 2014

스미스-렘리-오피츠 증후군은 상염색체 열성유전질환으로 콜레스테롤 합성의 장애로 나타나는 질병이다. 7-dehydrochlolesterol reductase 유전자의 변이로 인하여 콜레스테롤을 합성하지 못함으로써 정신지체, 자폐증, 발육부진, 내부장기 기형, 손과 발의 기형, 면역기능 저하, 소화기 및 시력의 문제 등이 나타난다. 이 질환은 경미한 증상에서부터 치명적인 증상까지 다양한 스펙트럼을 가진다. 저자들은 다양한 기형을 가진 환아에서 조기에 스미스-렘리-오피츠 증후군을 유전자 분석을 통하여 진단하였으며, 조기 진단 후 식이진행 및 기형에 대한 치료, 콜레스테롤을 보충 하였으며, 이를 문헌고찰과 함께 보고하는 바이다.