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Borecka O, Dutton JJ, Tang JCY, Fraser WD, Webb AR, Rhodes LE. Comparative Study of Healthy Older and Younger Adults Shows They Have the Same Skin Concentration of Vitamin D 3 Precursor, 7-Dehydrocholesterol, and Similar Response to UVR. Nutrients 2024; 16:1147. [PMID: 38674838 PMCID: PMC11053405 DOI: 10.3390/nu16081147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/05/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Vitamin D3 synthesis in human skin is initiated by solar ultraviolet radiation (UVR) exposure of precursor 7-dehydrocholesterol (7DHC), but influence of age on the early stage of vitamin D3 metabolism is uncertain. We performed a prospective standardised study in healthy ambulant adults aged ≥65 and ≤40 years examining (1) if baseline skin 7DHC concentration differs between younger and older adults and (2) the impact of older age on serum vitamin D3 response to solar simulated UVR. Eleven younger (18-40 years) and 10 older (65-89 years) adults, phototype I-III, received low-dose UVR (95% UVA, 5% UVB, 1.3 SED) to ~35% of the body surface area. Biopsies were taken for 7DHC assay from unexposed skin, skin immediately and 24 h post-UVR, and blood sampled at baseline, 24 h and 7 d post-UVR for vitamin D3 assay. Samples were analysed by HPLC-MS/MS. Baseline skin 7DHC (mean ± SD) was 0.22 ± 0.07 and 0.25 ± 0.08 µg/mg in younger versus older adults (no significant difference). Baseline serum vitamin D3 concentration was 1.5 ± 1.5 and 1.5 ± 1.7 nmol/L in younger versus older adults, respectively, and showed a significant increase in both groups post-UVR (no significant differences between age groups). Thus, skin 7DHC concentration was not a limiting factor for vitamin D3 production in older relative to younger adults. This information assists public health guidance on sun exposure/vitamin D nutrition, with particular relevance to the growing populations of healthy ambulant adults ≥65 years.
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Affiliation(s)
- Oktawia Borecka
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester M13 9PL, UK; (O.B.); (A.R.W.)
- Division of Musculoskeletal and Dermatological Sciences, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PL, UK
- Photobiology Unit, Dermatology Research Centre, Salford Royal Hospital, Northern Care Alliance NHS Foundation Trust, Manchester Academic Health Science Centre, Greater Manchester M6 8HD, UK
| | - John J. Dutton
- Bioanalytical Facility, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; (J.J.D.); (W.D.F.)
| | - Jonathan C. Y. Tang
- Bioanalytical Facility, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; (J.J.D.); (W.D.F.)
- Departments of Clinical Biochemistry and Endocrinology, Norfolk and Norwich University Hospital, Norwich NR4 7UY, UK
| | - William D. Fraser
- Bioanalytical Facility, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; (J.J.D.); (W.D.F.)
- Departments of Clinical Biochemistry and Endocrinology, Norfolk and Norwich University Hospital, Norwich NR4 7UY, UK
| | - Ann R. Webb
- Department of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester M13 9PL, UK; (O.B.); (A.R.W.)
| | - Lesley E. Rhodes
- Division of Musculoskeletal and Dermatological Sciences, School of Biological Sciences, Faculty of Biology Medicine and Health, University of Manchester, Manchester M13 9PL, UK
- Photobiology Unit, Dermatology Research Centre, Salford Royal Hospital, Northern Care Alliance NHS Foundation Trust, Manchester Academic Health Science Centre, Greater Manchester M6 8HD, UK
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Koczok K, Horváth L, Korade Z, Mezei ZA, Szabó GP, Porter NA, Kovács E, Mirnics K, Balogh I. Biochemical and Clinical Effects of Vitamin E Supplementation in Hungarian Smith-Lemli-Opitz Syndrome Patients. Biomolecules 2021; 11:biom11081228. [PMID: 34439893 PMCID: PMC8393612 DOI: 10.3390/biom11081228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/02/2021] [Accepted: 08/12/2021] [Indexed: 11/16/2022] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a severe monogenic disorder resulting in low cholesterol and high 7-dehydrocholesterol (7-DHC) levels. 7-DHC-derived oxysterols likely contribute to disease pathophysiology, and thus antioxidant treatment might be beneficial because of high oxidative stress. In a three-year prospective study, we investigated the effects of vitamin E supplementation in six SLOS patients already receiving dietary cholesterol treatment. Plasma vitamin A and E concentrations were determined by the high-performance liquid chromatography (HPLC) method. At baseline, plasma 7-DHC, 8-dehydrocholesterol (8-DHC) and cholesterol levels were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The clinical effect of the supplementation was assessed by performing structured parental interviews. At baseline, patients were characterized by low or low-normal plasma vitamin E concentrations (7.19-15.68 μmol/L), while vitamin A concentrations were found to be normal or high (1.26-2.68 μmol/L). Vitamin E supplementation resulted in correction or significant elevation of plasma vitamin E concentration in all patients. We observed reduced aggression, self-injury, irritability, hyperactivity, attention deficit, repetitive behavior, sleep disturbance, skin photosensitivity and/or eczema in 3/6 patients, with notable individual variability. Clinical response to therapy was associated with a low baseline 7-DHC + 8-DHC/cholesterol ratio (0.2-0.4). We suggest that determination of vitamin E status is important in SLOS patients. Supplementation of vitamin E should be considered and might be beneficial.
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Affiliation(s)
- Katalin Koczok
- Division of Clinical Genetics, Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (K.K.); (E.K.)
| | - László Horváth
- Department of Pharmaceutical Surveillance and Economics, Faculty of Pharmacy, University of Debrecen, 4032 Debrecen, Hungary;
| | - Zeljka Korade
- Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Zoltán András Mezei
- Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary;
| | - Gabriella P. Szabó
- Department of Pediatrics, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary;
| | - Ned A. Porter
- Department of Chemistry, Vanderbilt University, Nashville, TN 37240, USA;
| | - Eszter Kovács
- Division of Clinical Genetics, Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (K.K.); (E.K.)
| | - Károly Mirnics
- Departments of Psychiatry, Biochemistry & Molecular Biology, Pharmacology & Experimental Neuroscience and Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, NE 68106, USA;
| | - István Balogh
- Division of Clinical Genetics, Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (K.K.); (E.K.)
- Department of Human Genetics, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Correspondence: ; Tel.: +36-52-340-006
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Hirayama S, Nagasaka H, Honda A, Komatsu H, Kodama T, Inui A, Morioka I, Kaji S, Ueno T, Ihara K, Yagi M, Kizaki Z, Bessho K, Kondou H, Yorifuji T, Tsukahara H, Iijima K, Miida T. Cholesterol Metabolism Is Enhanced in the Liver and Brain of Children With Citrin Deficiency. J Clin Endocrinol Metab 2018; 103:2488-2497. [PMID: 29659898 DOI: 10.1210/jc.2017-02664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/02/2018] [Indexed: 02/07/2023]
Abstract
CONTEXT Citrin-deficient infants present neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), which resolves at 12 months. Thereafter, they have normal liver function associated with hypercholesterolemia, and a preference for lipid-rich carbohydrate-restricted diets. However, some develop adult-onset type II citrullinemia, which is associated with metabolic abnormalities. OBJECTIVES To identify the causes of hypercholesterolemia in citrin-deficient children post-NICCD. DESIGN AND SETTING We determined the concentrations of sterol markers of cholesterol synthesis, absorption, and catabolism by liquid chromatography-electrospray ionization-tandem mass spectrometry and evaluated serum lipoprotein profiles. SUBJECTS Twenty citrin-deficient children aged 5 to 13 years and 37 age-matched healthy children. INTERVENTION None. MAIN OUTCOME MEASURES Relationship between serum lipoproteins and sterol markers of cholesterol metabolism. RESULTS The citrin-deficient group had a significantly higher high-density lipoprotein cholesterol (HDL-C) concentration than did the control group (78 ± 11 mg/dL vs 62 ± 14 mg/dL, P < 0.001), whereas the two groups had similar low-density lipoprotein cholesterol and triglyceride concentrations. The concentrations of markers of cholesterol synthesis (lathosterol and 7-dehydrocholesterol) and bile acids synthesis (7α-hydroxycholesterol and 27-hydroxycholesterol) were 1.5- to 2.8-fold and 1.5- to 3.9-fold, respectively, higher in the citrin-deficient group than in the control group. The concentration of 24S-hydroxycholesterol, a marker of cholesterol catabolism in the brain, was 2.5-fold higher in the citrin-deficient group. In both groups, the HDL-C concentration was significantly positively correlated with that of 27-hydroxycholesterol, the first product of the alternative bile acid synthesis pathway. CONCLUSIONS HDL-C and sterol marker concentrations are elevated in citrin-deficient children post-NICCD. Moreover, cholesterol synthesis and elimination are markedly enhanced in the liver and brain of citrin-deficient children.
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Affiliation(s)
- Satoshi Hirayama
- Department of Clinical Laboratory Medicine, Juntendo University School of Medicine, Tokyo, Japan
| | - Hironori Nagasaka
- Department of Pediatrics, Takarazuka City Hospital, Takarazuka, Japan
| | - Akira Honda
- Joint Research Center and Division of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, Ibaraki, Japan
| | - Haruki Komatsu
- Department of Pediatrics, Toho University Sakura Medical Center, Sakura, Japan
| | - Takahiro Kodama
- Department of Gastroenterology and Hepatology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Ayano Inui
- Department of Pediatric Hepatology and Gastroenterology, Saiseikai Yokohamashi Tobu Hospital, Yokohama, Japan
| | - Ichiro Morioka
- Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Japan
| | - Shunsaku Kaji
- Department of Pediatrics, Tsuyama-Chuo Hospital, Okayama, Japan
| | - Tsuyoshi Ueno
- Department of Clinical Laboratory Medicine, Juntendo University School of Medicine, Tokyo, Japan
| | - Kenji Ihara
- Department of Pediatrics, Kyushu University Graduate School of Medical Science, Fukuoka, Japan
- Department of Pediatrics, Oita University, Faculty of Medicine, Yufu, Japan
| | - Mariko Yagi
- Department of Pediatrics, Nikoniko House Medical & Welfare Center, Kobe, Japan
| | - Zenro Kizaki
- Department of Pediatrics, Japanese Red Cross Kyoto Daiichi Hospital, Kyoto, Japan
| | - Kazuhiko Bessho
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Hiroki Kondou
- Department of Pediatrics, Kindai University Nara Hospital, Nara, Japan
| | - Tohru Yorifuji
- Division of Pediatric Endocrinology and Metabolism, Children's Medical Center, Osaka City General Hospital, Osaka, Japan
| | - Hirokazu Tsukahara
- Department of Pediatrics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Takashi Miida
- Department of Clinical Laboratory Medicine, Juntendo University School of Medicine, Tokyo, Japan
- Department of Clinical Laboratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
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Korade Ž, Liu W, Warren EB, Armstrong K, Porter NA, Konradi C. Effect of psychotropic drug treatment on sterol metabolism. Schizophr Res 2017; 187:74-81. [PMID: 28202290 PMCID: PMC5554466 DOI: 10.1016/j.schres.2017.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/30/2017] [Accepted: 02/01/2017] [Indexed: 01/08/2023]
Abstract
Cholesterol metabolism is vital for brain function. Previous work in cultured cells has shown that a number of psychotropic drugs inhibit the activity of 7-dehydrocholesterol reductase (DHCR7), an enzyme that catalyzes the final steps in cholesterol biosynthesis. This leads to the accumulation of 7-dehydrocholesterol (7DHC), a molecule that gives rise to oxysterols, vitamin D, and atypical neurosteroids. We examined levels of cholesterol and the cholesterol precursors desmosterol, lanosterol, 7DHC and its isomer 8-dehydrocholesterol (8DHC), in blood samples of 123 psychiatric patients on various antipsychotic and antidepressant drugs, and 85 healthy controls, to see if the observations in cell lines hold true for patients as well. Three drugs, aripiprazole, haloperidol and trazodone increased circulating 7DHC and 8DHC levels, while five other drugs, clozapine, escitalopram/citalopram, lamotrigine, olanzapine, and risperidone, did not. Studies in rat brain verified that haloperidol dose-dependently increased 7DHC and 8DHC levels, while clozapine had no effect. We conclude that further studies should investigate the role of 7DHC and 8DHC metabolites, such as oxysterols, vitamin D, and atypical neurosteroids, in the deleterious and therapeutic effects of psychotropic drugs. Finally, we recommend that drugs that increase 7DHC levels should not be prescribed during pregnancy, as children born with DHCR7 deficiency have multiple congenital malformations.
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Affiliation(s)
- Željka Korade
- Department of Pediatrics and Department of Biochemistry and Molecular Biology, UNMC, Omaha, NE 68198, United States
| | - Wei Liu
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Nashville, TN 37235, United States
| | - Emily B Warren
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37240, United States
| | - Kristan Armstrong
- Department of Psychiatry, Vanderbilt University, Nashville, TN 37212, United States
| | - Ned A Porter
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Nashville, TN 37235, United States
| | - Christine Konradi
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37240, United States; Department of Psychiatry, Vanderbilt University, Nashville, TN 37212, United States.
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Griffiths WJ, Abdel-Khalik J, Crick PJ, Ogundare M, Shackleton CH, Tuschl K, Kwok MK, Bigger BW, Morris AA, Honda A, Xu L, Porter NA, Björkhem I, Clayton PT, Wang Y. Sterols and oxysterols in plasma from Smith-Lemli-Opitz syndrome patients. J Steroid Biochem Mol Biol 2017; 169:77-87. [PMID: 26976653 PMCID: PMC5018427 DOI: 10.1016/j.jsbmb.2016.03.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 03/02/2016] [Accepted: 03/10/2016] [Indexed: 01/02/2023]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a severe autosomal recessive disorder resulting from defects in the cholesterol synthesising enzyme 7-dehydrocholesterol reductase (Δ7-sterol reductase, DHCR7, EC 1.3.1.21) leading to a build-up of the cholesterol precursor 7-dehydrocholesterol (7-DHC) in tissues and blood plasma. Although the underling enzyme deficiency associated with SLOS is clear there are likely to be multiple mechanisms responsible for SLOS pathology. In an effort to learn more of the aetiology of SLOS we have analysed plasma from SLOS patients to search for metabolites derived from 7-DHC which may be responsible for some of the pathology. We have identified a novel hydroxy-8-dehydrocholesterol, which is either 24- or 25-hydroxy-8-dehydrocholesterol and also the known metabolites 26-hydroxy-8-dehydrocholesterol, 4-hydroxy-7-dehydrocholesterol, 3β,5α-dihydroxycholest-7-en-6-one and 7α,8α-epoxycholesterol. None of these metabolites are detected in control plasma at quantifiable levels (0.5ng/mL).
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Affiliation(s)
- William J Griffiths
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
| | - Jonas Abdel-Khalik
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Peter J Crick
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Michael Ogundare
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | | | - Karin Tuschl
- Centre for Translational Omics, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Mei Kwun Kwok
- Centre for Translational Omics, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Brian W Bigger
- Stem Cell & Neurotherapies, Manchester Centre for Genomic Medicine, University of Manchester, Manchester M13 1PT, UK
| | - Andrew A Morris
- Willink Biochemical Genetics Unit, Genetic Medicine, St. Mary's Hospital, Oxford Road, Manchester M13 9WL, UK
| | - Akira Honda
- Tokyo Medical University, Ibaraki Medical Center, 3-20-1Chuoh, Ami, Ibaraki 300-0395, Japan
| | - Libin Xu
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
| | - Ned A Porter
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA
| | - Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet and Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Peter T Clayton
- Centre for Translational Omics, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Yuqin Wang
- College of Medicine, Grove Building, Swansea University, Singleton Park, Swansea SA2 8PP, UK.
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Radtke J, Schutkowski A, Brandsch C, Hirche F, Hasenkopf K, Stangl GI. Isolated Conglutin γ from Lupin, but not Phytate, Lowers Serum Cholesterol Without Influencing Vascular Lesion Development in the ApoE-deficient Mouse Model. Plant Foods Hum Nutr 2015; 70:113-118. [PMID: 25814378 DOI: 10.1007/s11130-015-0481-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Conglutin γ and phytate are considered as potential biofunctional compounds of lupin protein isolate, but their impact on vascular health is unknown. This study aimed to investigate the effect of conglutin γ and phytate, respectively, on circulating levels of sterols, markers of cholesterol biosynthesis and minerals, and on the development and progression of aortic lesions in apoE-deficient mice. To this end, mice were fed a western diet with either casein (200 g/kg; served as a control), conglutin γ from L. angustifolius (200 g/kg) or casein (200 g/kg) supplemented with phytate (5 g/kg) for 16 weeks. Here we found that conglutin γ but not phytate was capable of reducing the circulating concentration of cholesterol. Plasma levels of desmosterol and lathosterol as markers of the cholesterol synthesis were not affected, and 7-dehydrocholesterol was even higher in mice fed conglutin γ than in mice fed casein or casein + phytate. All mice developed pronounced aortic lesions, but histological characterization of plaque area and composition showed no differences between the three groups of mice. Conclusively, conglutin γ exerts cholesterol-lowering effects but appears to have no anti-atherosclerotic properties in the apoE-deficient mice. Phytate neither affected plasma cholesterol nor aortic lesion development.
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Affiliation(s)
- Juliane Radtke
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Von Danckelmann Platz 2, 06120, Halle (Saale), Germany
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Bzdúch V, Behúlová D, Skodová J, Skokňová M, Kozák L. [Historical aspects of the Smith-Lemli-Opitz syndrome]. Cas Lek Cesk 2014; 153:36-39. [PMID: 24506692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The new malformation syndrome was first described approximately 50 years ago in three unrelated patients in Department of Pediatrics at the University of Wisconsin, Madison, (Smith, Lemli, Opitz 1964). This syndrome was called RSH syndrome after the first 3 patients studied. First Slovak patient with phenotypic features of this new syndrome was described by professor Sršeň in 1972. In 1994 Tint from VA Medical Center, E. Orange, New Jersey analyzed plasma sterols of patient with Smith-Lemli-Opitz syndrome and found out that in addition to low plasma cholesterol level, the patient had 1000-fold increase of the plasma level of 7-dehydrocholesterol, the immediate precursor of cholesterol biosynthesis. After this biochemical discovery Smith-Lemli-Opitz syndrome became the metabolic-malformation syndrome with an exactly defined impairment of cholesterol metabolism. The first patient with biochemically proved Smith-Lemli-Opitz syndrome in Slovakia was described by Behulova et al. (1997) in cooperation with Department of Biochemistry and Medical Biotechnology, Federico II University in Naples, Italy. The three years later a screening method UV spectrometry of serum lipids for detection of 7-dehydrocholesterol was established in Department of Biochemistry, University Children´s Hospital in cooperation with the Institute of preventive and clinical medicine in Bratislava (Skodova et al.,2000). First results of molecular analysis of the 7-dehydrocholesterol reductase gene in 10 unrelated Czech and Slovak patients with Smith-Lemli-Opitz syndrome were reported by Kozak et al. (2000). The same year the first prenatal diagnosis of Smith-Lemli-Opitz syndrome by mutation analysis was achieved (Bzduch et al., 2000). Our research activities on this topic drew good response from abroad.
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Hall P, Michels V, Gavrilov D, Matern D, Oglesbee D, Raymond K, Rinaldo P, Tortorelli S. Aripiprazole and trazodone cause elevations of 7-dehydrocholesterol in the absence of Smith-Lemli-Opitz Syndrome. Mol Genet Metab 2013; 110:176-8. [PMID: 23628460 DOI: 10.1016/j.ymgme.2013.04.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 04/01/2013] [Accepted: 04/01/2013] [Indexed: 11/17/2022]
Abstract
Screening for Smith-Lemli-Opitz Syndrome (SLOS) using elevated 7-dehydrocholesterol (7DHC) as a marker is sensitive, but not always specific. Elevations of 7DHC can be seen in patients who do not have a defect in 7-dehydrocholesterol reductase. These results have often been attributed to medication artifacts, but specific causes have not been well reported. We examined the medical records of patients with elevated 7DHC to determine if they had been diagnosed with SLOS; and if they had not, to identify any common medications that may have caused the elevations. We found three individuals who were affected with SLOS, and 22 with elevated 7DHC in the absence of SLOS. Seven of these individuals underwent molecular testing which showed no mutations, while the other 15 were excluded based on clinical findings and other testing. The medication history of these individuals revealed aripiprazole and trazodone as common medications to all the false positive results.
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Affiliation(s)
- Patricia Hall
- Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
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Keller RK, Mitchell DA, Goulah CC, Fliesler SJ. Hepatic isoprenoid metabolism in a rat model of Smith-Lemli-Opitz Syndrome. Lipids 2013; 48:219-29. [PMID: 23361583 DOI: 10.1007/s11745-013-3762-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 01/08/2013] [Indexed: 02/06/2023]
Abstract
Elevated (4 to 7-fold) levels of urinary dolichol and coenzyme Q and substantially longer chain lengths for urinary dolichols have been reported in Smith-Lemli-Opitz Syndrome (SLOS) patients, compared to normal subjects. We investigated the possibility of similar alterations in hepatic, nonsterol isoprenoids in a well-established rat model of SLOS. In this model, the ratio of 7-dehydrocholesterol (7DHC) to cholesterol (Chol) in serum approached 15:1; however, total sterol mass in serum decreased by >80 %. Livers from treated rats had 7DHC/Chol ratios of ~32:1, but the steady-state levels of total sterols were >40 % those of livers from age-matched (3-month-old) control animals. No significant differences in the levels of LDL receptor or HMG-CoA reductase were observed. The levels of dolichol and coenzyme Q were elevated only modestly (by 64 and 31 %, respectively; p < 0.05, N = 6) in the livers of the SLOS rat model compared to controls; moreover, the chain lengths of these isoprenoids were not different in the two groups. We conclude that hepatic isoprenoid synthesis is marginally elevated in this animal model of SLOS, but without preferential shunting to the nonsterol branches (dolichol and coenzyme Q) of the pathway and without alteration of normal dolichol chain lengths.
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Affiliation(s)
- R Kennedy Keller
- Department of Molecular Medicine, University of South Florida, College of Medicine, Tampa, FL 33612, USA
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Roullet JB, Merkens LS, Pappu AS, Jacobs MD, Winter R, Connor WE, Steiner RD. No evidence for mevalonate shunting in moderately affected children with Smith-Lemli-Opitz syndrome. J Inherit Metab Dis 2012; 35:859-69. [PMID: 22391996 PMCID: PMC3404269 DOI: 10.1007/s10545-012-9453-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 12/29/2011] [Accepted: 01/10/2012] [Indexed: 10/28/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is caused by a genetic deficiency in 7-dehydrocholesterol (7-DHC) reductase (EC 1.3.1.21), the last enzyme of the cholesterol synthetic pathway. In SLOS, plasma cholesterol concentration is reduced and immediate precursor concentration (7-DHC) is elevated. Surprisingly, total sterol synthesis is reduced but HMG-CoA reductase activity, a rate-limiting enzyme in cholesterol synthesis is unaltered as judged by normal urinary excretion of mevalonic acid (MVA) (Pappu et al. J Lipid Res 43:1661-1669, 2002). These findings raise the possibility of increased diversion of MVA into the MVA shunt pathway away from sterol synthesis, by activation of the shunt pathway enzymes. To test this hypothesis, we measured the urinary excretion of 3-methylglutaconic acid (U-3MGC), a by-product of the shunt pathway, in 19 mildly to moderately severely affected SLOS subjects (ten males, nine females) receiving either a cholesterol-free or a high cholesterol diet, and in 20 age- and sex-matched controls. U-3MGC was similar in SLOS and controls, and was unaffected by dietary cholesterol intake. Further, no change in U-3MGC was observed in a subset of SLOS subjects (n = 9) receiving simvastatin. In contrast, U-MVA was reduced by cholesterol supplementation (~54%, p < 0.05) and by simvastatin (~50%, p < 0.04). There was no correlation between U-3MGC and either plasma sterol concentrations, urinary isoprenoids, or the subjects' clinical severity score. However U-3MGC was inversely correlated with age (p < 0.04) and body weight (p < 0.02), and higher in females than in males (~65%, p < 0.025). The data show that DHCR7 deficiency does not result in 3MGC accumulation in SLOS and suggest that the MVA shunt pathway is not activated in patients with the condition.
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Affiliation(s)
- Jean-Baptiste Roullet
- Department of Pediatrics, Oregon Health & Science University, 707 S.W. Gaines St., Portland, OR 97239-2998, USA.
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Desai NS, Tukvadze N, Frediani J, Kipiani M, Sanikidze E, Nichols MM, Hebbar G, Kempker RR, Mirtskhulava V, Kalandadze I, Seydafkan S, Sutaria N, Chen TC, Blumberg HM, Ziegler TR, Tangpricha V. Effects of sunlight and diet on vitamin D status of pulmonary tuberculosis patients in Tbilisi, Georgia. Nutrition 2012; 28:362-6. [PMID: 22304856 PMCID: PMC3303957 DOI: 10.1016/j.nut.2011.08.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 08/19/2011] [Accepted: 08/19/2011] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Vitamin D deficiency is common in tuberculosis (TB) and this may modulate immune responses. This study investigated vitamin D status in patients with TB and examined the sources of vitamin D in Tbilisi, Georgia. METHODS We measured plasma 25-hydroxyvitamin D (25[OH]D) and dietary vitamin D intake in patients with pulmonary TB (n = 85) in Tbilisi, Georgia. To determine the impact of season on vitamin D status, we tested the in vitro conversion of 7-dehydrocholesterol (7-DHC) to previtamin D(3) after sunlight exposure. RESULTS In subjects with TB, mean plasma 25(OH)D concentrations were 14.4 ± 7.0 ng/mL, and vitamin D insufficiency (25[OH]D <30 ng/mL) occurred in 97% of subjects. The dietary sources of vitamin D were mainly fish, eggs, and butter. The daily intake was well below recommended daily intakes in subjects with TB (172 ± 196 IU). The conversion of 7-DHC to previtamin D(3) was undetectable from October to March and highest in June and July from 11:00 to 14:00 h. CONCLUSION An insufficient vitamin D dietary intake and a limited production of vitamin D from sunlight for most of the year may explain the high prevalence of vitamin D insufficiency in patients with TB in Tbilisi.
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Affiliation(s)
- Nirali S. Desai
- Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA 30322
| | - Nestani Tukvadze
- National Center for Tuberculosis and Lung Diseases (NCTBLD), Tbilisi, 0101, Republic of Georgia
| | - Jennifer Frediani
- Atlanta Clinical and Translational Science Institute, Emory University School of Medicine, Atlanta, GA, USA 30322
- Nutrition and Health Sciences Program, Graduate Division of Biological and Biomedical Sciences, Emory University Laney Graduate School, Atlanta, GA, USA 30322
| | - Maia Kipiani
- National Center for Tuberculosis and Lung Diseases (NCTBLD), Tbilisi, 0101, Republic of Georgia
| | - Eka Sanikidze
- National Center for Tuberculosis and Lung Diseases (NCTBLD), Tbilisi, 0101, Republic of Georgia
| | - Memorie M. Nichols
- Nutrition and Health Sciences Program, Graduate Division of Biological and Biomedical Sciences, Emory University Laney Graduate School, Atlanta, GA, USA 30322
| | - Gautam Hebbar
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA 30322
| | - Russell R. Kempker
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA 30303
| | - Veriko Mirtskhulava
- National Center for Tuberculosis and Lung Diseases (NCTBLD), Tbilisi, 0101, Republic of Georgia
| | - Iagor Kalandadze
- National Center for Tuberculosis and Lung Diseases (NCTBLD), Tbilisi, 0101, Republic of Georgia
| | - Shabnam Seydafkan
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA 30322
| | - Nilay Sutaria
- Section of Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, MA, USA 02118
| | - Tai C. Chen
- Section of Endocrinology, Diabetes and Nutrition, Department of Medicine, Boston University School of Medicine, Boston, MA, USA 02118
| | - Henry M. Blumberg
- Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA 30322
- Atlanta Clinical and Translational Science Institute, Emory University School of Medicine, Atlanta, GA, USA 30322
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA 30303
| | - Thomas R. Ziegler
- Atlanta Clinical and Translational Science Institute, Emory University School of Medicine, Atlanta, GA, USA 30322
- Nutrition and Health Sciences Program, Graduate Division of Biological and Biomedical Sciences, Emory University Laney Graduate School, Atlanta, GA, USA 30322
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA 30322
| | - Vin Tangpricha
- Atlanta Clinical and Translational Science Institute, Emory University School of Medicine, Atlanta, GA, USA 30322
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA 30322
- Staff Physician, Atlanta VA Medical Center, Decatur, GA USA 30033
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de Sain-van der Velden MGM, Verrips A, Prinsen BHCMT, de Barse M, Berger R, Visser G. Elevated cholesterol precursors other than cholestanol can also be a hallmark for CTX. J Inherit Metab Dis 2008; 31 Suppl 2:S387-93. [PMID: 18949577 DOI: 10.1007/s10545-008-0963-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Revised: 09/10/2008] [Accepted: 09/22/2008] [Indexed: 12/21/2022]
Abstract
Cerebrotendinous xanthomatosis (CTX) is an inborn error of bile acid synthesis in which hepatic conversion of cholesterol to cholic and chenodeoxycholic acids is impaired. Patients have abnormal bile alcohols in urine, normal to increased plasma cholesterol concentrations and increased concentrations of plasma cholestanol. Little is known about cholesterol precursors in CTX, however. We studied cholesterol and phytosterol profiles in two siblings with CTX during follow-up. While cholesterol concentrations were low in both patients, plasma cholestanol was 6-fold higher compared to control values. In addition, both siblings had a more than 100-fold increase in 7-dehydrocholesterol (7DHC) and 8-dehydrocholesterol (8DHC). Lathosterol, lanosterol and sitosterol were increased in both patients while concentrations of desmosterol and campesterol were normal. In addition, plasma lathosterol/cholesterol ratios were significantly elevated. After treatment with chenodeoxycholate, both patients showed a marked decrease in cholestanol, 7DHC, 8DHC, lathosterol, lanosterol and sitosterol. In addition, the lathosterol/cholesterol ratio normalized, indicating that overall cholesterol synthesis was sufficiently suppressed. This study shows that elevated cholesterol precursors, other than cholestanol, can be a hallmark for CTX.
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Affiliation(s)
- M G M de Sain-van der Velden
- Department of Metabolic and Endocrine Diseases, University Medical Centre Utrecht, HP KC 02.069.1, Lundlaan 6 3584 CX, Utrecht, The Netherlands.
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Haas D, Armbrust S, Haas JP, Zschocke J, Mühlmann K, Fusch C, Neumann LM. Smith-Lemli-Opitz syndrome with a classical phenotype, oesophageal achalasia and borderline plasma sterol concentrations. J Inherit Metab Dis 2005; 28:1191-6. [PMID: 16435228 DOI: 10.1007/s10545-005-0168-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The diagnostic biochemical hallmarks of Smith-Lemli-Opitz syndrome (SLOS) are elevated concentrations of the cholesterol precursors 7- and 8-dehydrocholesterol (7- and 8-DHC). We describe a patient with classical SLOS phenotype and oesophageal achalasia, which has not been reported in SLOS patients before. Plasma 7-DHC and 8-DHC were only marginally elevated. The diagnosis was confirmed by sterol analysis in cultured skin fibroblasts and mutation analysis.
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Affiliation(s)
- D Haas
- Division of Inherited Metabolic Diseases, University Children's Hospital, Im Neuenheimer Feld 150, 69120 Heidelberg, Germany.
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14
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Abstract
Smith-Lemli-Opitz syndrome is a condition of impaired cholesterol synthesis that is caused by mutations in DHCR7 encoding 7-dehydrocholesterol-Delta7 reductase. Birth defects and mental retardation are characteristic. Deficient plasma and tissue cholesterol and excess cholesterol precursors 7 and 8 dehydrocholesterol (7DHC and 8DHC) contribute to the pathogenesis. Cholesterol is transported to tissues via lipoproteins. We measured the effect of dietary cholesterol (egg yolk) on plasma lipoproteins to evaluate this potential treatment. We used the enzymatic method to measure total sterols in lipoproteins (n=12) and plasma (n=16). In addition, we analyzed individual plasma sterols by a gas chromatographic method. Samples were evaluated after 3 wk of a cholesterol-free diet and after 6-19 mo of dietary cholesterol. We also analyzed the distribution of sterols in lipoproteins and the apolipoprotein E genotype. Dietary cholesterol significantly increased the total sterols in plasma (2.22 +/- 0.13 to 3.10 +/- 0.22; mean +/- SEM; p < 0.002), in LDL (0.98 +/- 0.13 to 1.52 +/- 0.17 mM), and in HDL (0.72 +/- 0.04 to 0.92 +/- 0.07). Plasma cholesterol increased (1.78 +/- 0.16 to 2.67 +/- 0.25 mM; p < 0.007) and plasma 7DHC decreased in 10 children, but the mean decrease was not significant. The distribution of individual sterols in each lipoprotein fraction was similar to the distribution in plasma. The baseline cholesterol and the response to dietary cholesterol was the same in children with 3/3 and 3/4 apolipoprotein E genotypes. Dietary cholesterol increased total sterols in plasma, LDL, and HDL in children with Smith-Lemli-Opitz syndrome. These favorable increases in the lipoproteins are potentially therapeutic for this condition.
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Affiliation(s)
- Louise S Merkens
- Department of Pediatrics, Child Development and Rehabilitation Center, Doernbecher Children's Hospital, OR Health & Science University, CDRC-F, 707 SW Gaines, Portland, OR 97239, USA
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Fliesler SJ, Peachey NS, Richards MJ, Nagel BA, Vaughan DK. Retinal degeneration in a rodent model of Smith-Lemli-Opitz syndrome: electrophysiologic, biochemical, and morphologic features. ACTA ACUST UNITED AC 2004; 122:1190-200. [PMID: 15302661 PMCID: PMC2865831 DOI: 10.1001/archopht.122.8.1190] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To assess the electrophysiologic, histologic, and biochemical features of an animal model of Smith-Lemli-Opitz syndrome (SLOS). METHODS Sprague-Dawley rats were treated with AY9944, a selective inhibitor of 3beta-hydroxysterol-Delta(7)-reductase (the affected enzyme in SLOS). Dark- and light-adapted electroretinograms were obtained from treated and control animals. From each animal, 1 retina was analyzed by microscopy, and the contralateral retina plus serum samples were analyzed for sterol composition. The main outcome measures were rod and cone electroretinographic amplitudes and implicit times, outer nuclear layer (ONL) thickness, rod outer segment length, pyknotic ONL nucleus counts, and the 7-dehydrocholesterol/cholesterol mole ratio in the retina and serum. RESULTS By 10 weeks' postnatal age, rod and cone electroretinographic wave amplitudes in AY9944-treated animals were significantly reduced and implicit times were significantly increased relative to controls. Maximal rod photoresponse and gain values were reduced approximately 2-fold in treated animals relative to controls. The ONL thickness and average rod outer segment length were reduced by approximately 18% and 33%, respectively, and ONL pyknotic nucleus counts were approximately 4.5-fold greater in treated animals relative to controls. The retinal pigment epithelium of treated animals contained massive amounts of membranous/lipid inclusions not routinely observed in controls. The 7-dehydrocholesterol/cholesterol mole ratios in treated retinas and serum samples were approximately 5:1 and 9:1, respectively, whereas the ratios in control tissues were essentially zero. CONCLUSIONS This rodent model exhibits the key biochemical hallmarks associated with SLOS and displays electrophysiologic deficits comparable to or greater than those observed in the human disease. Clinical Relevance These results predict retinal degeneration in patients with SLOS, particularly those with the more severe (type II) form of the disease, and may be more broadly relevant to other inborn errors of cholesterol biosynthesis. This animal model may also be of use in evaluating therapeutic treatments for SLOS and in understanding the slow phototransduction kinetics observed in patients with SLOS.
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Affiliation(s)
- Steven J Fliesler
- Department of Ophthalmology, Saint Louis University School of Medicine, MO 63104-1540, USA.
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16
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Nowaczyk MJM, Martin-Garcia D, Aquino-Perna A, Rodriguez-Vazquez M, McCaughey D, Eng B, Nakamura LM, Waye JS. Founder effect for the T93MDHCR7 mutation in Smith-Lemli-Opitz syndrome. ACTA ACUST UNITED AC 2004; 125A:173-6. [PMID: 14981719 DOI: 10.1002/ajmg.a.20676] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive MCA-MR disorder caused by mutations within the 7-dehydrocholesterol reductase gene, DHCR7. The diagnosis is based on the biochemical findings of elevated plasma 7-dehydrocholesterol (7DHC) levels. It is a panethnic condition with variable mutation frequencies in different populations. Ten Cuban patients and four Canadian patients of Mediterranean ancestry with SLOS are reported herein. All these patients are at the mild end of the clinical spectrum (the highest Kelley-Hennekam severity score was 28 in one patient). All patients had genotypes which were compound heterozygous or homozygous for T93M; in all the Mediterranean patients the T93M mutation appeared to be associated with the J haplotype. Another compound heterozygote for T93M was of Ukrainian/Irish ancestry; in this patient the T93M was associated with a new haplotype designated K. The T93M mutation was initially reported as the most common in a series of patients from Italy. Our identification of a single haplotype associated with the T93M mutation in patients whose ancestors originate in the region of the Mediterranean Sea basin suggests a founder effect.
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Scalco FB, Cruzes VM, Vendramini RC, Brunetti IL, Moretti-Ferreira D. Diagnosis of Smith-Lemli-Opitz syndrome by ultraviolet spectrophotometry. Braz J Med Biol Res 2003; 36:1327-32. [PMID: 14502364 DOI: 10.1590/s0100-879x2003001000008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder due to an inborn error of cholesterol metabolism, characterized by congenital malformations, dysmorphism of multiple organs, mental retardation and delayed neuropsychomotor development resulting from cholesterol biosynthesis deficiency. A defect in 3 -hydroxysteroid-delta7-reductase (delta7-sterol-reductase), responsible for the conversion of 7-dehydrocholesterol (7-DHC) to cholesterol, causes an increase in 7-DHC and frequently reduces plasma cholesterol levels. The clinical diagnosis of SLOS cannot always be conclusive because of the remarkable variability of clinical expression of the disorder. Thus, confirmation by the measurement of plasma 7-DHC levels is needed. In the present study, we used a simple, fast, and selective method based on ultraviolet spectrophotometry to measure 7-DHC in order to diagnose SLOS. 7-DHC was extracted serially from 200 l plasma with ethanol and n-hexane and the absorbance at 234 and 282 nm was determined. The method was applied to negative control plasma samples from 23 normal individuals and from 6 cases of suspected SLOS. The method was adequate and reliable and 2 SLOS cases were diagnosed.
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Affiliation(s)
- F B Scalco
- Serviço de Aconselhamento Genético, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brasil
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Langius FAA, Waterham HR, Romeijn GJ, Oostheim W, de Barse MMJ, Dorland L, Duran M, Beemer FA, Wanders RJA, Poll-The BT. Identification of three patients with a very mild form of Smith-Lemli-Opitz syndrome. Am J Med Genet A 2003; 122A:24-9. [PMID: 12949967 DOI: 10.1002/ajmg.a.20207] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive malformation syndrome characterized by mental retardation, congenital anomalies, and growth deficiency. The syndrome is caused by a block in cholesterol biosynthesis at the level of 7-dehydrocholesterol reductase (7-DHCR), which results in elevated levels of the cholesterol precursor 7-dehydrocholesterol (7-DHC) and its isomer 8-dehydrocholesterol (8-DHC). We report on three patients from two families with a very mild clinical presentation of SLOS. Their plasma cholesterol values were normal and their plasma levels of 7- and 8- DHC were only slightly elevated. In cultured skin fibroblasts, a significant residual 7-DHCR activity was found. All three patients were compound heterozygotes for a novel mutation affecting translation initiation (M1L). Two of them had the common IVS8-1G>C null mutation and the third patient an E448K mutation in the 7-DHCR gene. Our findings emphasize the importance of using a sensitive method for measuring precursors of cholesterol in combination with mutation analysis to analyze patients with only minimal clinical SLOS-like signs.
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Digilio MC, Marino B, Giannotti A, Dallapiccola B, Opitz JM. Specific congenital heart defects in RSH/Smith-Lemli-Opitz syndrome: postulated involvement of the sonic hedgehog pathway in syndromes with postaxial polydactyly or heterotaxia. Birth Defects Res A Clin Mol Teratol 2003; 67:149-53. [PMID: 12797454 DOI: 10.1002/bdra.10010] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND RSH/Smith-Lemli-Opitz syndrome is an autosomal recessive syndrome due to an inborn error of cholesterol metabolism and is characterized by developmental delay, facial anomalies, hypospadias, congenital heart defect (CHD), postaxial polydactyly, and 2-3 toe syndactyly. CHD is found in half of the propositi, and a specific association with atrioventricular canal defect (AVCD) and anomalous pulmonary venous return has been demonstrated. METHODS We report on an additional patient with RSH/SLOS presenting with complete AVCD and anomalous pulmonary venous return, and discuss the possible relationship of the Sonic Hedgehog (SHH) pathway as causative factor of these CHDs and those in heterotaxia patients with postaxial polydactyly syndromes. RESULTS Anatomic similarities between heterotaxia and CHDs of several syndromes with postaxial polydactyly have been noted previously, considering the frequent association of AVCD with common atrium in these conditions. It is known that both CHDs of heterotaxia and postaxial polydactyly can be related to abnormalities of the SHH pathway. Cholesterol has a critical role in the formation of normally active hedgehog proteins. It could be hypothesized that specific types of CHDs in RSH/SLOS can be caused by modifications of the SHH protein related to the defect of cholesterol biosynthesis. CONCLUSIONS The specific association of AVCD and anomalous pulmonary venous return in patients with RSH/SLOS and the finding of AVCD +/- common atrium in several syndromes with polydactyly leads to the hypothesis that heterotaxia due to SHH anomalies could be involved in a large spectrum of conditions. Perturbations in different components of the SHH pathway could lead to several developmental errors presenting with partially overlapping clinical manifestations.
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Abstract
Soon after the discovery of reduced cholesterol synthesis in the Smith-Lemli-Opitz syndrome (SLOS), several trials with dietary supplementation were initiated with the aim of increasing cholesterol and reducing the de novo synthesis and accumulation of 7- and 8-dehydrocholesterol (DHC). Dietary cholesterol raises cholesterol levels in the circulation with only marginal effects on levels of DHC. Photosensitivity and polyneuropathy have been reported to be improved by the treatment, but other effects have been difficult to evaluate. In order to see whether inhibition of hydroxymethylglutaryl CoA reductase is of benefit, two of our patients have been treated with simvastatin in addition to the long-term treatment with cholesterol and bile acids. Absolute as well as relative levels of DHC were reduced. In one patient, creatine kinase increased moderately after 2 months of treatment. In the other patient, the treatment had to be interrupted because of hepatotoxic side effects with a marked increase in alanine aminotransferase and aggravation of the hypocholesterolemia and photosensitivity. We conclude that even if the levels of accumulated intermediates can be reduced, treatment with a statin may be harmful in some patients with SLOS.
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Affiliation(s)
- Lena Starck
- Sachs' Children's Hospital, Department of Paediatrics, Karolinska Institute, Stockholm, Sweden.
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Abstract
A wide variety of unsaturated sterols can accumulate in eukaryotic cells as a consequence of normal metabolism, genetic disorders, and actions of enzyme inhibitors. Resolving these sterol mixtures into individual components by conventional chromatographic methods is inefficient because unsaturated sterols differ little in polarity, hydrophobicity, and volatility. Although sterol mixtures are well-resolved by silver-ion high performance liquid chromatography (Ag(+)-HPLC), existing methods require derivatization to acetates for best results, and the isocratic mobile phases lead to long analysis times and low sensitivity for late-eluting sterols. We show that these problems can be overcome with ternary gradient elution using acetone, hexanes, and acetonitrile. Separation of a mixture of 20 underivatized sterols gave dramatically shortened analysis times, with good peak shapes for both early- and late-eluting components. In a similar separation of blood sterols from a patient with Smith-Lemli-Opitz syndrome, the band for 7-dehydrocholesterol was much narrower than with isocratic elution. Column re-equilibration was rapid, and the separations could be monitored with ultraviolet spectroscopy at 210 nm, which affords universal, non-destructive detection of unsaturated sterols. Also discussed are retention mechanisms and reproducibility of Ag(+)-HPLC separations. The overall results represent a major advance in chromatographic methods for resolving mixtures of unsaturated sterols differing in the number and position of olefinic bonds.
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Affiliation(s)
- Hui Shan
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street, Houston, TX 77005-1892, USA
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Starck L, Lövgren-Sandblom A, Björkhem I. Cholesterol treatment forever? The first Scandinavian trial of cholesterol supplementation in the cholesterol-synthesis defect Smith-Lemli-Opitz syndrome. J Intern Med 2002; 252:314-21. [PMID: 12366604 DOI: 10.1046/j.1365-2796.2002.01037.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
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.
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Affiliation(s)
- L Starck
- Sachs' Children's Hospital, S-11883 Stockholm, Sweden.
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Patrono C, Dionisi-Vici C, Giannotti A, Bembi B, Digilio MC, Rizzo C, Purificato C, Martini C, Pierini R, Santorelli FM. Two novel mutations of the human Δ7-sterol reductase (DHCR7) gene in children with Smith–Lemli–Opitz syndrome. Mol Cell Probes 2002; 16:315-8. [PMID: 12270273 DOI: 10.1006/mcpr.2002.0426] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We analyzed seven unrelated children with the Smith-Lemli-Opitz syndrome (SLOS) for mutations in the delta7-sterol reductase gene by using SSCP and direct sequencing. We identified two novel mutations (V330M and R363C) in the DHCR7 gene. Reported mutations found in this study were T93M (3/14 alleles), E448K (2/14), and W151X, G244R, P329L, and R446Q (each found in one allele). The so-called common IVS8-1 G --> C was found in three alleles, confirming its relative rarity among Italian SLOS families. By using a scoring system, clinical severity did not seem to correlate with 7DHC levels and type of mutation. Expanding the spectrum of mutations in SLOS, our study does not support direct genotype-phenotype correlation.
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Affiliation(s)
- C Patrono
- Molecular Medicine, Metabolism, and Genetics, IRCCS - Children's Hospital Bambino Gesù, Rome, Italy
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Xiong Q, Ruan B, Whitby FG, Tuohy RP, Belanger TL, Kelley RI, Wilson WK, Schroepfer GJ. A colorimetric assay for 7-dehydrocholesterol with potential application to screening for Smith-Lemli-Opitz syndrome. Chem Phys Lipids 2002; 115:1-15. [PMID: 12047895 DOI: 10.1016/s0009-3084(01)00205-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS; MIM 270400) is a genetic disorder characterized by hypocholesterolemia and elevated 7-dehydrocholesterol (7DHC) levels resulting from mutations affecting 7-dehydrocholesterol reductase. We describe a colorimetric assay for 7DHC with potential application to large-scale screening for SLOS. Reaction of 7DHC and its esters with the Liebermann-Burchard reagent resulted in a brief initial absorbance at 510 nm (pink color) followed by an absorbance at 620 nm (blue color) after 2 min, while cholesterol samples were essentially colorless. The assay could identify typical SLOS blood samples by their pink color and increased absorbance at 620 nm after 2 min. Colorimetric identification of mild SLOS cases requires monitoring of the transient absorbance at 510 nm, which must be detected immediately after rapid, consistent mixing of the reagents. The need for special mixing devices and rigorous validation precludes sporadic use of the assay for diagnosing suspected SLOS cases. We also studied the stability of 7DHC in dried SLOS blood spots on Guthrie cards, which are widely used for archiving neonatal blood. Decomposition of 7DHC was effectively retarded by storage at low temperature and by precoating of the cards with antioxidants. The combined results provide a foundation for development of a simple, automated test for SLOS screening.
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Affiliation(s)
- Quanbo Xiong
- Department of Biochemistry and Cell Biology, Rice University, MS140, 6100 Main Street, Houston, TX 77005-1892, USA
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Prasad C, Marles S, Prasad AN, Nikkel S, Longstaffe S, Peabody D, Eng B, Wright S, Waye JS, Nowaczyk MJM. Smith-Lemli-Opitz syndrome: new mutation with a mild phenotype. Am J Med Genet 2002; 108:64-8. [PMID: 11857552 DOI: 10.1002/ajmg.10211] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) (Online Mendelian Inheritance in Man, OMIM, 2001, http://www.ncbi.nlm.nih.gov/omim/ for SLOS, MIM 270400) is an autosomal recessive disorder of cholesterol biosynthesis caused by mutations of the 3beta-hydroxysterol Delta(7)-reductase gene, DHCR7. We report on a female infant with an exceptionally mild phenotype of SLOS, in whom molecular studies identified a new mutation in DHCR7. The proposita initially presented with feeding difficulties, failure to thrive, hypotonia, mild developmental delay, and oral tactile aversion. She had minor facial anomalies and 2-3 syndactyly of her toes in both feet. The plasma cholesterol was borderline low at 2.88 mmol/L (normal 2.97-4.40 mmol/L). Elevated plasma 7-dehydrocholesterol level of 200.0 micromol/L confirmed the clinical diagnosis of SLOS. Molecular analysis demonstrated compound heterozygosity for IVS8-1G -->C and Y280C, a new missense mutation in DHCR7. Since the other mutation in this patient is a known null mutation, this newly discovered mutation is presumably associated with significant residual enzyme activity and milder expression of clinical phenotype.
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Affiliation(s)
- Chitra Prasad
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Canada
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Corso G, Rossi M, De BD, Rossi I, Parenti G, Dello RA. Effects of sample storage on 7- and 8-dehydrocholesterol levels analysed on whole blood spots by gas chromatography-mass spectrometry-selected ion monitoring. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 766:365-70. [PMID: 11824824 DOI: 10.1016/s0378-4347(01)00520-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) patients have increased 7- and 8-dehydrocholesterol (DHC) concentrations. Using gas chromatography-mass spectrometry with selected ion monitoring we investigated whether storage time (24 h, 7 and 30 days, and 22 months at room temperature or at 4 degrees C) affected DHC concentrations in whole blood spots (WBSs) from SLOS patients and normal controls. Our results suggest that WBS sterol analysis can be used for SLOS screening and possibly related inborn errors of sterol metabolism with a 100% sensitivity and specificity on specimens stored for up to 30 days, either at room temperature or 4 degrees C. After 22 months of storage at both temperature SLOS samples can be indistinguishable from control samples. Therefore, great caution should be used to exclude SLOS by sterol analysis of WBSs stored for a long time.
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Affiliation(s)
- Gaetano Corso
- Dipartimento di Biochimica e Biotecnologie Mediche, Università di Napoli Federico II, Naples, Italy
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Nowaczyk MJ, Siu VM, Krakowiak PA, Porter FD. Adrenal insufficiency and hypertension in a newborn infant with Smith-Lemli-Opitz syndrome. Am J Med Genet 2001; 103:223-5. [PMID: 11745994 DOI: 10.1002/ajmg.1545.abs] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder caused by mutations in the 7-dehydrocholesterol reductase gene, DHCR7. The diagnosis is based on the biochemical findings of elevated plasma 7-dehydrocholesterol (7DHC) levels. Adrenal insufficiency with hyponatremia has been reported in 3 patients with severe SLOS; in those cases it was thought to be caused by aldosterone deficiency because it responded to mineralocorticoid replacement. We present a fourth patient with a severe form of SLOS and adrenal insufficiency who had unexplained persistent hypertension, a combination of signs that has not been reported previously in SLOS.
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Affiliation(s)
- M J Nowaczyk
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
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28
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Johnson DW, ten Brink HJ, Jakobs C. A rapid screening procedure for cholesterol and dehydrocholesterol by electrospray ionization tandem mass spectrometry. J Lipid Res 2001; 42:1699-705. [PMID: 11590227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
The mono-(dimethylaminoethyl) succinyl (MDMAES) ester is a new derivative for rapid, mild, and sensitive electrospray ionization tandem mass spectrometry (ESI-MS/MS) analysis of cholesterol and dehydrocholesterol. It is an order of magnitude more sensitive than the previous most practical alternative, the N-methylpyridyl ether derivative. The MDMAES derivative was used to develop a rapid screening procedure for the biochemical diagnosis of Smith-Lemli-Opitz syndrome (SLOS) by measuring the dehydrocholesterol/cholesterol ratio in plasma (5 microl) and plasma spotted onto filter paper. Details of the synthesis of [25,26,26,26,27,27,27-(2)H7]-7-dehydrocholesterol, used as a standard for quantitation, are included. The measurement of total sterols as MDMAES esters, after base hydrolysis of plasma, afforded a dehydrocholesterol/cholesterol ratio of 0.05-2.95 for SLOS patient samples (n = 5) compared with 0.001-0.003 for normal adult controls (n = 20). Direct hexane extraction of plasma without base hydrolysis enabled the measurement of free sterols with a total sample analysis time of <1 h. The free dehydrocholesterol/cholesterol ratio was 0.10-4.47 for SLOS patient samples (n = 5) and 0.003-0.011 for normal adult controls (n = 20).
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Affiliation(s)
- D W Johnson
- Department of Chemical Pathology, Women's and Children's Hospital, 72 King William Road, North Adelaide, South Australia 5006, Australia.
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29
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Tatidis L, Vitols S, Gruber A, Paul C, Axelson M. Cholesterol catabolism in patients with acute myelogenous leukemia and hypocholesterolemia: suppressed levels of a circulating marker for bile acid synthesis. Cancer Lett 2001; 170:169-75. [PMID: 11463495 DOI: 10.1016/s0304-3835(01)00592-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Hypocholesterolemia is a frequent finding in patients with acute myelogenous leukemia (AML) and in other types of malignancies. Since bile acids are major excretion products of cholesterol, the hepatic degradation of cholesterol to bile acids was investigated in AML patients by analyzing a circulating marker for bile acid synthesis. In addition, plasma levels of a marker for cholesterol synthesis were determined. The plasma levels of 7alpha-hydroxy-4-cholesten-3-one, reflecting bile acid production, were markedly lower in patients with AML than in healthy controls. The median levels were 3.3 and 18.5ng/ml (P<0.0001) in the AML patients (n=29) and the healthy subjects (n=16), respectively. The plasma levels of 7-dehydrocholesterol, reflecting hepatic cholesterol synthesis, were similar for the AML patients and the controls. The results show that the conversion of cholesterol to bile acids was suppressed in AML patients, a phenomenon that may result in a decreased intestinal absorption of cholesterol and subsequent hypocholesterolemia.
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Affiliation(s)
- L Tatidis
- Division of Clinical Pharmacology, Department of Medicine, Karolinska Institute and Hospital, S-171 76 Stockholm, Sweden.
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30
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Abstract
Smith-Lemli-Opitz syndrome (OMIM 270400) (SLOS) is caused by inherited enzymatic deficiency of 3beta-hydroxysterol-Delta7-reductase (7-dehydrocholesterol-Delta7-reductase, DHCR7). SLOS is diagnosed clinically by the demonstration of elevated levels of 7-dehydrocholesterol (7DHC) in body fluids or tissues. SLOS is associated with mental retardation of variable degree and severe behavior abnormalities. The physical abnormalities range from minor facial anomalies to lethal malformations of the central nervous system, heart, kidneys, and other organs. The exact incidence of SLOS is not known. Although there exist estimates of the incidence of SLOS ranging from 1 in 20,000 to 1 in 60,000, no prospective studies of the incidence of SLOS, based on the clinical data and biochemical diagnosis of SLOS, have been performed. Five unrelated cases of SLOS were diagnosed in Ontario during a 12-month period. The diagnoses were made based on the demonstration of elevated 7DHC in plasma or amniotic fluid. The birth rate for Ontario for that period was 132,000 births. The incidence of SLOS in Ontario was at least 1 in 26,500 pregnancies in 1999-2000. Given that 86% of the population of Ontario is of European origin, the incidence of SLOS in the Ontario population of European origin was at least 1 in 22,700. As infants with mild forms of SLOS born during this period may remain undiagnosed, these numbers likely are underestimates. This observation has implications for prenatal and newborn screening for this potentially treatable inherited disorder.
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Affiliation(s)
- M J Nowaczyk
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
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31
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Rivas Crespo F. [Smith-Lemli-Opitz syndrome]. An Esp Pediatr 2001; 55:94-5. [PMID: 11412481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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Einarsson C, Hillebrant CG, Axelson M. Effects of treatment with deoxycholic acid and chenodeoxycholic acid on the hepatic synthesis of cholesterol and bile acids in healthy subjects. Hepatology 2001; 33:1189-93. [PMID: 11343248 DOI: 10.1053/jhep.2001.23790] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The degradation of cholesterol to bile acids is regulated by a negative-feedback mechanism by the bile acids, especially the hydrophobic bile acids, returning to the liver via the portal vein. Chenodeoxycholic acid (CDCA) is a potent suppressor of the cholesterol 7alpha-hydroxylase, the rate-determining enzyme in bile acid formation. CDCA may also suppress hepatic 3-hydroxy-3-methyl glutaryl coenzyme A (HMG CoA) reductase, the rate-limiting enzyme in cholesterol synthesis. Conflicting reports have appeared regarding the suppression on bile acid synthesis by the most hydrophobic bile acid of human bile, deoxycholic acid (DCA). To study the suppressive effects of CDCA and DCA on hepatic cholesterol and bile acid synthesis in humans, 10 healthy subjects were treated with CDCA or DCA for 3 weeks in a randomized cross-over study with a washout period of 4 weeks in between. Serum levels of 7alpha-hydroxy-4-cholesten-3-one, reflecting cholesterol 7alpha-hydroxylase activity, and 7-dehydrocholesterol, reflecting HMG CoA reductase activity, and bile acids were repeatedly measured during the study periods. After 3 weeks of treatment with CDCA or DCA, CDCA constituted 70% and DCA 74% of the total serum bile acids, respectively. CDCA and DCA decreased the serum levels of 7alpha-hydroxy-4-cholesten-3-one by 80% and 75%, respectively. Negative correlations between the percentages of CDCA and DCA and the serum concentration of 7alpha-hydroxy-4-cholesten-3-one were obtained. CDCA reduced the serum level of 7-dehydrocholesterol by 29%, whereas treatment with DCA tended to increase the level of 7-dehydrocholesterol. Treatment of healthy subjects with CDCA and DCA reduces bile acid synthesis. CDCA also inhibits cholesterol synthesis, whereas DCA does not.
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Affiliation(s)
- C Einarsson
- Department of Medicine, Division of Gastroenterology and Hepatology, Karolinska Institutet at Huddinge University Hospital, Stockholm, Sweden.
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Kwiecinski GG, Zhiren L, Chen TC, Holick MF. Observations on serum 25-hydroxyvitamin D and calcium concentrations from wild-caught and captive neotropical bats, Artibeus jamaicensis. Gen Comp Endocrinol 2001; 122:225-31. [PMID: 11316428 DOI: 10.1006/gcen.2001.7635] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Most bats of the suborder Microchiroptera are nocturnal, actively avoid sunlight, and eat mineral-poor diets. In those bats previously studied with respect to mineral metabolism, extensive bone remodeling occurs, and it has been suggested that calcium has been an important constraint on reproduction. There have been no previous studies of vitamin D or its metabolites in microchiropteran bats with respect to calcium metabolism. Reported is the utilization of current advances for the determination of serum levels of the vitamin D metabolite 25-hyroxyvitamin D (25-OH-D) in a neotropical bat, Artibeus jamaicensis. Serum from wild-caught animals contained low levels of 25-OH-D (5.6 +/- 3.0 ng/ml, n = 8). Bats maintained on a vitamin-D-supplemented diet had higher serum 25-OH-D levels and when the diet containing vitamin D was discontinued, mean serum 25-OH-D levels declined significantly after 6 months. Serum calcium concentrations in wild-caught bats (8.5 +/- 0.4 mg%) showed very little variation and were not significantly different in any of the vitamin-D-supplemented animals. A pairwise correlation analysis between 25-OH-D and serum calcium levels revealed no linear correlation. The results indicate either that 25-OH-D does not appear to play a key role or that low levels of 25-OH-D may be adequate in regulating serum calcium levels in this bat.
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Affiliation(s)
- G G Kwiecinski
- Department of Biology, University of Scranton, Scranton, Pennsylvania, 18510-4625, USA
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34
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Björkhem I, Starck L, Andersson U, Lütjohann D, von Bahr S, Pikuleva I, Babiker A, Diczfalusy U. Oxysterols in the circulation of patients with the Smith-Lemli-Opitz syndrome: abnormal levels of 24S- and 27-hydroxycholesterol. J Lipid Res 2001; 42:366-71. [PMID: 11254748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Infants with the cholesterol synthesis defect Smith- Lemli-Opitz syndrome (SLO) have reduced activity of the enzyme 7-dehydrocholesterol-7-reductase and accumulate 7-dehydrocholesterol, with the highest concentration in the brain. As a result of the generally reduced content of cholesterol, plasma levels of oxysterols would be expected to be reduced. 24S-hydroxycholesterol is almost exclusively formed in the brain, whereas 27-hydroxycholesterol is mainly formed from extrahepatic and extracerebral cholesterol. In accordance with the expectations, sterol-correlated plasma levels of 24S-hydroxycholesterol were reduced in infants with SLO (by about 50%). In contrast, the sterol-correlated levels of 27-hydroxycholesterol in the circulation were markedly increased. No side-chain oxidized metabolites of 7-dehydrocholesterol were detected in the circulation. Recombinant human CYP27 had markedly lower 27-hydroxylase activity toward 7-dehydrocholesterol than towards cholesterol. HEK293 cells expressing 24S-hydroxylase active toward cholesterol had no significant activity towards 7-dehydrocholesterol. The plasma levels of 3 beta,7 alpha-dihydroxy-5-cholestenoic in the patients acid were reduced, suggesting a generally reduced metabolism of 27-oxygenated steroids. It is concluded that the accumulation of 7-dehydrocholesterol in the brains of patients with SLO reduces formation of 24S-hydroxycholesterol. The condition is associated with markedly increased circulating levels of 27-hydroxycholesterol, most probably due to reduced metabolism of this oxysterol. We discuss the possibility that the circulating levels of 24S-hydroxycholesterol may be used as a marker for the severity of the disease.--Björkhem, I., L. Starck, U. Andersson, D. Lütjohann, S. von Bahr, I. Pikuleva, A. Babiker, and U. Diczfaulsy. Oxysterols in the circulation of patients with the Smith-Lemli-Opitz syndrome: abnormal levels of 24S- and 27-hydroxycholesterol. J. Lipid Res. 2001. 42: 366--371.
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Affiliation(s)
- I Björkhem
- Division of Clinical Chemistry, Huddinge University Hospital, Sweden.
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Abstract
In recent years, several inherited human disorders caused by defects in cholesterol biosynthesis have been identified. These are characterized by malformations, multiple congenital anomalies, mental and growth retardation and/or skeletal and skin abnormalities indicating a pivotal role of cholesterol in morphogenesis and embryonic development. The first recognized and most common of these developmental disorders is Smith-Lemli-Opitz syndrome, an autosomal recessive trait caused by mutations in the DHCR7 gene resulting in a deficiency of the encoded sterol Delta(7)-reductase, alternatively called 7-dehydrocholesterol reductase (EC 1.3.1.21). This enzyme catalyzes the final step in cholesterol biosynthesis, which is the reduction of the Delta(7) double bond of 7-dehydrocholesterol to produce cholesterol.
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Affiliation(s)
- H R Waterham
- Laboratory for Genetic Metabolic Diseases (F0-224), Department of Paediatrics, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, P.O. Box 22700, 1100 DE, Amsterdam, The Netherlands.
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36
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GarcíaFuentes E. [Biochemical diagnosis of Smith-Lemli-Opitz syndrome in a patient with congenital adrenal hyperplasia]. An Esp Pediatr 2000; 53:482-7. [PMID: 11141372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
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.
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Linck LM, Lin DS, Flavell D, Connor WE, Steiner RD. Cholesterol supplementation with egg yolk increases plasma cholesterol and decreases plasma 7-dehydrocholesterol in Smith-Lemli-Opitz syndrome. Am J Med Genet 2000; 93:360-5. [PMID: 10951458 DOI: 10.1002/1096-8628(20000828)93:5<360::aid-ajmg4>3.0.co;2-p] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS), an autosomal recessive condition comprising multiple malformations, mental retardation, and growth failure, results from reduced activity of the final enzyme in cholesterol biosynthesis, 7-dehydrocholesterol Delta(7)-reductase (DHCR7). Reduced plasma and tissue cholesterol concentrations and accumulation of cholesterol precursors including 7-dehydrocholesterol (7-DHC) are characteristic biochemical abnormalities. While it is still unclear what role these potentially toxic precursors have in the pathogenesis of this disorder, the accumulation of 7-DHC in the brain has been associated with impaired learning in rats and oxidized 7-DHC has been shown to induce growth retardation in cultured rat embryos. We hypothesized that supplemental dietary cholesterol would increase plasma cholesterol levels and suppress synthesis of 7-DHC and other abnormal sterols in individuals with SLOS. After baseline sterol levels were obtained, patients were provided supplemental cholesterol as egg yolk. Plasma sterols were analyzed by capillary-column gas chromatography over time in four children with SLOS. When evaluated at 4-8 weeks after the initiation of cholesterol supplementation, there was a marked increase in mean plasma cholesterol, from 53 mg/dl to 82 mg/dl. While the percent of total sterols as 7-DHC decreased from 15% to 10%, there was no change in total plasma 7-DHC levels. However, when evaluated 35-90 weeks after the institution of cholesterol supplementation, mean plasma 7-DHC decreased, from 11.3 mg/dl to 3.5 mg/dl (-67%, P < 0.05), along with an increase in mean plasma cholesterol from 53 mg/dl to 114 mg/dl (+116%, P < 0.05). These results support the hypothesis that over time dietary cholesterol supplementation from egg yolk increases the plasma cholesterol levels and decreases levels of 7-DHC which may be toxic. These data have important therapeutic implications in the management of SLOS.
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Affiliation(s)
- L M Linck
- Department of Pediatrics and Department of Molecular and Medical Genetics, Child Development and Rehabilitation Center, Doernbecher Children's Hospital, Oregon Health Sciences University, Portland, Oregon, USA
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Jira PE, Wevers RA, de Jong J, Rubio-Gozalbo E, Janssen-Zijlstra FS, van Heyst AF, Sengers RC, Smeitink JA. Simvastatin. A new therapeutic approach for Smith-Lemli-Opitz syndrome. J Lipid Res 2000; 41:1339-46. [PMID: 10946022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
The Smith-Lemli-Opitz syndrome (SLOS) is caused by deficient Delta(7)-dehydrocholesterol reductase, which catalyzes the final step of the cholesterol biosynthetic pathway, resulting in low cholesterol and high concentrations of its direct precursors 7-dehydrocholesterol (7DHC) and 8DHC. We hypothesized that i) 7DHC and 8DHC accumulation contributes to the poor outcome of SLOS patients and ii) blood exchange transfusions with hydroxymethylglutaryl (HMG)-CoA reductase inhibition would improve the precursor-to-cholesterol ratio and may improve the clinical outcome of SLO patients. First, an in vitro study was performed to study sterol exchange between plasma and erythrocyte membranes. Second, several exchange transfusions were carried out in vivo in two SLOS patients. Third, simvastatin was given for 23 and 14 months to two patients. The in vitro results illustrated rapid sterol exchange between plasma and erythrocyte membranes. The effect of exchange transfusion was impressive and prompt but the effect on plasma sterol levels lasted only for 3 days. In contrast, simvastatin treatment for several months demonstrated a lasting improvement of the precursor-to-cholesterol ratio in plasma, erythrocyte membranes, and cerebrospinal fluid (CSF). Plasma precursor concentrations decreased to 28 and 33% of the initial level, respectively, whereas the cholesterol concentration normalized by a more than twofold increase. During the follow-up period all morphometric parameters improved. The therapy was well tolerated and no unwanted clinical side effects occurred. This is the first study in which the blood cholesterol level in SLOS patients is normalized with a simultaneous significant decrease in precursor levels. There was a lasting biochemical improvement with encouraging clinical improvement. Statin therapy is a promising novel approach in SLOS that deserves further studies in larger series of patients.
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Affiliation(s)
- P E Jira
- Department of Metabolic Diseases, University Hospital Nijmegen, 6500 HB Nijmegen, The Netherlands
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39
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Nowaczyk MJ. Plasma measurement of 7-dehydrocholesterol to detect carriers of Smith-Lemli-Opitz syndrome. Prenat Diagn 2000; 20:168. [PMID: 10694693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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40
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Rizzo C, Dionisi-Vici C, D'Ippoliti M, Fina F, Sabetta G, Federici G. A simple and rapid HPLC method for simultaneous determination of plasma 7-dehydrocholesterol and vitamin E: its application in Smith-Lemli-Opitz patients. Clin Chim Acta 2000; 291:97-102. [PMID: 10612721 DOI: 10.1016/s0009-8981(99)00197-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- C Rizzo
- Department of Metabolism, IRCCS 'Bambino Gesù' Children's Research Hospital, Piazza S. Onofrio 4, 00165, Rome, Italy.
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41
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Anstey AV, Ryan A, Rhodes LE, Charman CR, Arlett CF, Tyrrell RM, Taylor CR, Pearse AD. Characterization of photosensitivity in the Smith-Lemli-Opitz syndrome: a new congenital photosensitivity syndrome. Br J Dermatol 1999; 141:406-14. [PMID: 10583043 DOI: 10.1046/j.1365-2133.1999.03032.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Photosensitivity has recently been reported as a feature of the Smith-Lemli-Opitz syndrome (SLO). The aim of this study was to establish the photobiological features of this disorder and to examine the hypothesis that the photosensitivity is caused by the high levels of 7-dehydrocholesterol found in SLO. All known cases of SLO in the U.K. were reviewed and clinical details of photosensitivity were recorded in detail. The action spectrum of the photosensitive eruption was defined by monochromator light testing. Thirteen of the 23 subjects (57%) had severe photosensitivity, and in 10 there was no photosensitivity. No correlation was identified between levels of 7-dehydrocholesterol and severity of photosensitivity, suggesting that the photosensitivity in SLO is not caused by a direct phototoxic effect mediated by 7-dehydrocholesterol. A novel pattern of photosensitivity was observed, with onset of a sunburn-like erythema on sun-exposed skin within minutes of sun exposure, which persisted in most cases for up to 24-48 h before fading. Monochromator light testing in three subjects showed an ultraviolet (UV) A-mediated photosensitivity eruption with greatest photosensitivity at 350 nm. Photosensitivity is a common and prominent feature of SLO and appears to be UVA-mediated. Elucidation of its biochemical basis may provide insight into normal cutaneous protective mechanisms against UVA-induced photodamage, and also sun sensitivity in general.
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Affiliation(s)
- A V Anstey
- Photodermatology Unit, University of Wales College of Medicine, University Hospital of Wales, Cardiff CF4 4XN, U.K
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Abstract
Smith-Lemli-Opitz (SLO or RSH) syndrome is characterized by multiple congenital anomalies, mental retardation, and defective growth; it results from an inherited defect in the biosynthesis of cholesterol. Patients have elevated plasma concentrations of 7-dehydrocholesterol, the immediate biosynthetic precursor of cholesterol and most also have low circulating levels of cholesterol. To understand better the biochemical basis of clinical variability, we evaluated cholesterol biosynthesis in lymphoblasts from 3 unrelated SLOS patients with distinct phenotypes. One patient has "type I SLOS", the second has the more severe "type II SLOS" and the third is classified as atypical and had been postulated to have a defect in sterol transport. The lymphoblasts of each patient show normal subcellular localization of cholesterol and 7-dehydrocholesterol by gradient fractionation. Biochemical differences in the ability of the lymphoblasts to convert 7-dehydrocholesterol to cholesterol are described and correspond to the severity of disease (type II > type I > atypical). Recently, the gene responsible for most SLOS cases (DHCR7) was mapped to chromosome 11 and mutations in DHCR7 were found in each of these patients. The biochemical differences described here likely result from the different mutations observed in DHCR7.
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Affiliation(s)
- D W Neklason
- Department of Human Genetics and The Eccles Program in Human Molecular Biology and Genetics, University of Utah, Salt Lake City, Utah, USA
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Haghiri N, Menget A, Laitier V, Fromentin C, Nocton F, Kalach N. [Smith-Lemli-Opitz syndrome]. Arch Pediatr 1999; 6:536-9. [PMID: 10370810 DOI: 10.1016/s0929-693x(99)80561-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Smith-Lemli-Opitz syndrome (SLOS) is an autosomic recessive metabolic affection. Children affected by SLOS exhibit a defect in cholesterol biosynthesis associated with a high concentration of cholesterol precursor 7 dehydrocholesterol (7 DHC) and its isomers, which is due to an enzymatic block at the level of delta-7-DHC reductase. SLOS has been subdivided into two types on the basis of clinical severity: type I is the classic and type II is the severe one. CASE REPORT A full term female was born from a pregnancy complicated by oligoamniosis and intra-uterine growth retardation. The neurologic status was immediately impaired with severe hypotonia, absence of reflexes, and abnormal crying. She exhibited multiple congenital anomalies with a facial dysmorphia, anomalies of members, unicornus uterus and a pyloric stenosis. Plasmatic concentration exhibited a normal cholesterolemia contrasting with an elevated level of 7 and 8 DHC. Major alimentary tract defect led to enteral and parenteral nutrition. The severe neurological defect led to death on the 16th day of life. CONCLUSION Despite normal blood cholesterol levels that can be attributed to enteral and parenteral nutrition, the severity of clinical findings and the lethal course permit to classify this case as type II.
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Affiliation(s)
- N Haghiri
- Service de pédiatrie, CHG de Creil, France
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Andersson HC, Frentz J, Martínez JE, Tuck-Muller CM, Bellizaire J. Adrenal insufficiency in Smith-Lemli-Opitz syndrome. Am J Med Genet 1999; 82:382-4. [PMID: 10069708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
We describe three unrelated patients with adrenal insufficiency and RSH or Smith-Lemli-Opitz syndrome (SLOS), a disorder due to deficient synthesis of cholesterol. These patients presented with hyponatremia, hyperkalemia, and decreased aldosterone-to-renin ratio, which is a sensitive measure of the renin-aldosterone axis. All patients had profound serum total cholesterol deficiency (14-31 mg/dl) and marked elevation of 7-dehydrocholesterol (10-45 mg/ dl). Two patients were newborn infants with 46, XY karyotypes and complete failure to masculinize; one of these patients also had cortisol deficiency. Both patients died within 10 days of birth of cardiopulmonary complications while on adrenal replacement therapy. The third patient diagnosed with SLOS at birth presented at age 7months with fever and diarrhea and was noted to have profound hyponatremia. This patient is maintaining normal serum electrolytes on mineralocorticoid replacement. We conclude that adrenal insufficiency may be a previously undetected and treatable manifestation in SLOS. We hypothesize that deficiency of cholesterol, an adrenal hormone precursor, may lead to insufficient synthesis of adrenal steroid hormones.
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Affiliation(s)
- H C Andersson
- Human Genetics Program, Hayward Genetics Center, Tulane University Medical School, New Orleans, Louisiana 70112, USA.
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Bodamer OA, Craigen WJ. Importance of measuring plasma cholesterol precursors. Am J Med Genet 1999; 82:199. [PMID: 9934989 DOI: 10.1002/(sici)1096-8628(19990115)82:2<199::aid-ajmg19>3.0.co;2-q] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Axelson M, Angelin B, Hillebrant CG, Reihnér E, Einarsson C. The level of 7-dehydrocholesterol in plasma reflects the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase in the human liver. Biochim Biophys Acta 1998; 1394:153-7. [PMID: 9795194 DOI: 10.1016/s0005-2760(98)00104-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Plasma levels of the cholesterol precursor 7-dehydrocholesterol (7-DHC) were compared with activities of the rate-limiting enzyme in cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase assayed in liver biopsies from patients undergoing cholecystectomy. Some patients were treated with cholestyramine, deoxycholic acid or chenodeoxycholic acid prior to surgery in order to alter the activity of the enzyme. The median level of 7-DHC and the activity of HMG-CoA reductase in the untreated group were 55 ng/ml and 98 pmol/min/mg protein, respectively. The sterol levels and enzyme activities were increased in patients treated with cholestyramine (85 ng/ml and 439 pmol/min/mg protein) and deoxycholic acid (86 ng/ml and 173 pmol/min/mg protein) and decreased in patients treated with chenodeoxycholic acid (38 ng/ml and 51 pmol/min/mg protein). There was a strong positive correlation (rs=0.75, P<0.0005) between the plasma levels of 7-DHC and the activities of hepatic HMG-CoA reductase in these patients. This correlation was further improved when the plasma levels of 7-DHC were expressed relative to those of cholesterol (rs=0.90, P<0.0001). The results show that the level of 7-DHC in plasma reflects the activity of HMG-CoA reductase in the liver.
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Affiliation(s)
- M Axelson
- Department of Clinical Chemistry, Karolinska Hospital, Karolinska Institutet, S-171 76 Stockholm, Sweden.
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Abstract
Smith-Lemli-Opitz syndrome (SLO) is caused by inherited enzymatic deficiency of 7-dehydrocholesterol-delta7-reductase and resultant cholesterol deficiency. It comprises a characteristic combination of facial features, malformations, and mental retardation. We report on three related patients (two brothers and their first cousin) with mental retardation and minimal physical signs in whom the diagnosis of SLO was delayed for a number of years. The presence of a third-degree relative in the absence of consanguinity in this family supports the proposed high population carrier frequency. Our report suggests that cases of mild SLO remain undiagnosed and untreated, and that awareness of this common cause of mental retardation is low.
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Affiliation(s)
- M J Nowaczyk
- Department of Pathology and Laboratory Medicine, Hamilton Health Sciences Corporation and McMaster University, Ontario, Canada.
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Abstract
The RSH/Smith-Lemli-Opitz syndrome (RSH/SLOS) is an autosomal recessive malformation syndrome comprising microcephaly, developmental and growth retardation, characteristic facial anomalies, midline cleft palate, and genital and limb anomalies. Recently, biochemical evidence of an inborn error of cholesterol biosynthesis at the level of 7-dehydrocholesterol (7DHC) reductase was reported in children and adults with RSH/SLOS. We report on two sibs with a variant form of RSH/SLOS whose sterol metabolism in cultured lymphoblasts is abnormal but differs from that of patients with classical RSH/SLOS. The children have relatively mild physical and developmental abnormalities, but a phenotype still consistent with the diagnosis of RSH/SLOS. Their plasma cholesterol levels are only mildly depressed, and they have less markedly increased plasma levels of 7DHC than most patients with classical RSH/SLOS. Cultured lymphoblasts from our patients accumulated 7DHC to the same degree as classical RSH/SLOS lymphoblast when grown with cholesterol-depleted fetal calf serum. However, unlike other RSH/SLOS cells, the increase in cellular 7DHC levels was not suppressed when the cells were grown in the presence of cholesterol from untreated fetal calf serum. The parents' sterol metabolism was also strikingly abnormal in that the levels of 7DHC in their lymphoblasts were markedly elevated compared with those of lymphoblasts from other RSH/SLOS parents. Our findings suggest that these mildly affected RSH/SLOS sibs may have a genetic disorder of sterol metabolism that is related to but biochemically different from classical RSH/SLOS, possibly one affecting intracellular transport of sterols.
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Affiliation(s)
- A J Anderson
- Department of Pediatrics, Madigan Army Medical Center, Tacoma, Washington, USA
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Ryan AK, Bartlett K, Clayton P, Eaton S, Mills L, Donnai D, Winter RM, Burn J. Smith-Lemli-Opitz syndrome: a variable clinical and biochemical phenotype. J Med Genet 1998; 35:558-65. [PMID: 9678700 PMCID: PMC1051366 DOI: 10.1136/jmg.35.7.558] [Citation(s) in RCA: 187] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We have reviewed all known UK cases of Smith-Lemli-Opitz syndrome. Among 49 cases with proven 7-dehydrocholesterol reductase deficiency, half had been terminated or had died in infancy. The minimum incidence is 1 in 60,000. The frequent occurrence of hypospadias may account for 71% of recognised cases being male. Important common features which emerged include short thumbs, severe photosensitivity, aggressive behaviour, and atrioventricular septal defect. The typical facial appearance becomes less obvious with age and 20% of cases did not have 2/3 toe syndactyly. Biochemical measurements of serum 7-dehydrocholesterol did not correlate with clinical severity.
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Affiliation(s)
- A K Ryan
- Department of Human Genetics, University of Newcastle upon Tyne, UK
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Honda M, Tint GS, Honda A, Nguyen LB, Chen TS, Shefer S. 7-Dehydrocholesterol down-regulates cholesterol biosynthesis in cultured Smith-Lemli-Opitz syndrome skin fibroblasts. J Lipid Res 1998; 39:647-57. [PMID: 9548596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The Smith-Lemli-Opitz syndrome (SLOS) is a common birth defect-mental retardation syndrome caused by a defect in the enzyme that reduces 7-dehydrocholesterol to cholesterol. Because of this block, patients' plasma cholesterol levels are generally low while 7-dehydrocholesterol concentrations are markedly elevated. In addition, plasma total sterols are abnormally low and correlate negatively with the percent of 7-dehydrocholesterol (r = -0.65, P < 0.0001) suggesting that 7-dehydrocholesterol might inhibit the activity of HMG-CoA reductase. Cultured skin fibroblasts from SLOS patients grown in fetal bovine serum or for 1 day in delipidated medium contain little 7-dehydrocholesterol (3 +/- 1% of total sterols) and HMG-CoA reductase activities are indistinguishable from that measured in control cells. However, raising the 7-dehydrocholesterol concentration to 20 +/- 3% of total sterols, equal to the mean proportion in plasma of SLOS patients, by either growing cells for 1 week in delipidated medium or adding 20 microg/ml 7-dehydrocholesterol directly to the cells reduced HMG-CoA reductase activities from 74 +/- 7 to 9 +/- 2 pmol/min per mg protein, or from 92 +/- 22 to 16 +/- 4 pmol/min per mg protein, respectively (P < 0.01). In contrast, adding 20 microg/ml cholesterol evoked a 2- to 4-fold lesser suppression of activity (39 +/- 8 pmol/min per mg protein, P < 0.05, vs. 7-dehydrocholesterol). HMG-CoA synthase and LDL binding were inhibited equally by 7-dehydrocholesterol and cholesterol. Ketaconazole prevented the down-regulation of HMG-CoA reductase by 7-dehydrocholesterol, suggesting that an hydroxylated derivative of 7-dehydrocholesterol may be especially important in suppressing cholesterol synthesis. These results demonstrate that 7-dehydrocholesterol, perhaps as an hydroxylated derivative(s), is a very effective feedback inhibitor of HMG-CoA reductase.
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Affiliation(s)
- M Honda
- Department of Medicine, The Liver Center, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark 07103, USA
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