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Miyazaki S, Shimizu N, Miyahara H, Teranishi H, Umeda R, Yano S, Shimada T, Shiraishi H, Komiya K, Katoh A, Yoshimura A, Hanada R, Hanada T. DHCR7 links cholesterol synthesis with neuronal development and axonal integrity. Biochem Biophys Res Commun 2024; 712-713:149932. [PMID: 38626530 DOI: 10.1016/j.bbrc.2024.149932] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/03/2024] [Accepted: 04/10/2024] [Indexed: 04/18/2024]
Abstract
The DHCR7 enzyme converts 7-DHC into cholesterol. Mutations in DHCR7 can block cholesterol production, leading to abnormal accumulation of 7-DHC and causing Smith-Lemli-Opitz syndrome (SLOS). SLOS is an autosomal recessive disorder characterized by multiple malformations, including microcephaly, intellectual disability, behavior reminiscent of autism, sleep disturbances, and attention-deficit/hyperactivity disorder (ADHD)-like hyperactivity. Although 7-DHC affects neuronal differentiation in ex vivo experiments, the precise mechanism of SLOS remains unclear. We generated Dhcr7 deficient (dhcr7-/-) zebrafish that exhibited key features of SLOS, including microcephaly, decreased neural stem cell pools, and behavioral phenotypes similar to those of ADHD-like hyperactivity. These zebrafish demonstrated compromised myelination, synaptic anomalies, and neurotransmitter imbalances. The axons of the dhcr7-/- zebrafish showed increased lysosomes and attenuated autophagy, suggesting that autophagy-related neuronal homeostasis is disrupted.
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Affiliation(s)
- Shuya Miyazaki
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan; Department of Respiratory Medicine and Infectious Diseases, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Nobuyuki Shimizu
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Hiroaki Miyahara
- Department of Neuropathology, Institute for Medical Science of Aging, Aichi Medical University, Aichi, Japan
| | - Hitoshi Teranishi
- Department of Neurophysiology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Ryohei Umeda
- Department of Advanced Medical Sciences, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Shinji Yano
- Institute for Research Management, Oita University, Yufu, Oita, Japan
| | - Tatsuo Shimada
- Oita Medical Technology School, Japan College of Judo-Therapy, Acupuncture & Moxibustion Therapy, Oita, Japan
| | - Hiroshi Shiraishi
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Kosaku Komiya
- Department of Respiratory Medicine and Infectious Diseases, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Akira Katoh
- Department of Clinical Pharmacology & Therapeutics, Oita University, Yufu, Oita, Japan
| | - Akihiko Yoshimura
- Department of Microbiology and Immunology, Keio University School of Medicine, Tokyo, Japan
| | - Reiko Hanada
- Department of Neurophysiology, Oita University Faculty of Medicine, Yufu, Oita, Japan
| | - Toshikatsu Hanada
- Department of Cell Biology, Oita University Faculty of Medicine, Yufu, Oita, Japan.
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Gabor K, Mesev EV, Madenspacher J, Meacham J, Rai P, Moon S, Wassif CA, Shaikh SR, Tucker CJ, Karmaus P, Bianconi S, Porter FD, Fessler MB. Sterol biosynthesis regulates TLR signaling and the innate immune response in a Smith-Lemli-Opitz syndrome model. J Clin Invest 2024; 134:e167633. [PMID: 38236648 PMCID: PMC10940081 DOI: 10.1172/jci167633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2024] Open
Affiliation(s)
- Kristin Gabor
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Emily V Mesev
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Jennifer Madenspacher
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Julie Meacham
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Prashant Rai
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Sookjin Moon
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Christopher A Wassif
- Section on Molecular Dysmorphology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Saame Raza Shaikh
- Department of Nutrition, Gillings School of Global Public Health and School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - C J Tucker
- Fluorescence Microscopy and Imaging Center, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Peer Karmaus
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Simona Bianconi
- Section on Molecular Dysmorphology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Forbes D Porter
- Section on Molecular Dysmorphology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Michael B Fessler
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
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Freel BA, Kelvington BA, Sengupta S, Mukherjee M, Francis KR. Sterol dysregulation in Smith-Lemli-Opitz syndrome causes astrocyte immune reactivity through microglia crosstalk. Dis Model Mech 2022; 15:dmm049843. [PMID: 36524414 PMCID: PMC10655813 DOI: 10.1242/dmm.049843] [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: 08/15/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022] Open
Abstract
Owing to the need for de novo cholesterol synthesis and cholesterol-enriched structures within the nervous system, cholesterol homeostasis is critical to neurodevelopment. Diseases caused by genetic disruption of cholesterol biosynthesis, such as Smith-Lemli-Opitz syndrome, which is caused by mutations in 7-dehydrocholesterol reductase (DHCR7), frequently result in broad neurological deficits. Although astrocytes regulate multiple neural processes ranging from cell migration to network-level communication, immunological activation of astrocytes is a hallmark pathology in many diseases. However, the impact of DHCR7 on astrocyte function and immune activation remains unknown. We demonstrate that astrocytes from Dhcr7 mutant mice display hallmark signs of reactivity, including increased expression of glial fibrillary acidic protein (GFAP) and cellular hypertrophy. Transcript analyses demonstrate extensive Dhcr7 astrocyte immune activation, hyper-responsiveness to glutamate stimulation and altered calcium flux. We further determine that the impacts of Dhcr7 are not astrocyte intrinsic but result from non-cell-autonomous effects of microglia. Our data suggest that astrocyte-microglia crosstalk likely contributes to the neurological phenotypes observed in disorders of cholesterol biosynthesis. Additionally, these data further elucidate a role for cholesterol metabolism within the astrocyte-microglia immune axis, with possible implications in other neurological diseases.
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Affiliation(s)
- Bethany A. Freel
- Basic Biomedical Sciences, University of South Dakota, Vermillion, SD 57069, USA
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Benjamin A. Kelvington
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Sonali Sengupta
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Malini Mukherjee
- Functional Genomics and Bioinformatics Core, Sanford Research, Sioux Falls, SD 57104, USA
| | - Kevin R. Francis
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57105, USA
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Tomita H, Hines KM, Herron JM, Li A, Baggett DW, Xu L. 7-Dehydrocholesterol-derived oxysterols cause neurogenic defects in Smith-Lemli-Opitz syndrome. eLife 2022; 11:e67141. [PMID: 36111785 PMCID: PMC9519149 DOI: 10.7554/elife.67141] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [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: 02/01/2021] [Accepted: 09/15/2022] [Indexed: 11/13/2022] Open
Abstract
Defective 3β-hydroxysterol-Δ7 -reductase (DHCR7) in the developmental disorder, Smith-Lemli-Opitz syndrome (SLOS), results in a deficiency in cholesterol and accumulation of its precursor, 7-dehydrocholesterol (7-DHC). Here, we show that loss of DHCR7 causes accumulation of 7-DHC-derived oxysterol metabolites, premature neurogenesis from murine or human cortical neural precursors, and depletion of the cortical precursor pool, both in vitro and in vivo. We found that a major oxysterol, 3β,5α-dihydroxycholest-7-en-6-one (DHCEO), mediates these effects by initiating crosstalk between glucocorticoid receptor (GR) and neurotrophin receptor kinase TrkB. Either loss of DHCR7 or direct exposure to DHCEO causes hyperactivation of GR and TrkB and their downstream MEK-ERK-C/EBP signaling pathway in cortical neural precursors. Moreover, direct inhibition of GR activation with an antagonist or inhibition of DHCEO accumulation with antioxidants rescues the premature neurogenesis phenotype caused by the loss of DHCR7. These results suggest that GR could be a new therapeutic target against the neurological defects observed in SLOS.
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Affiliation(s)
- Hideaki Tomita
- Department of Medicinal Chemistry, University of WashingtonSeattleUnited States
| | - Kelly M Hines
- Department of Medicinal Chemistry, University of WashingtonSeattleUnited States
| | - Josi M Herron
- Department of Medicinal Chemistry, University of WashingtonSeattleUnited States
| | - Amy Li
- Department of Medicinal Chemistry, University of WashingtonSeattleUnited States
| | - David W Baggett
- Department of Medicinal Chemistry, University of WashingtonSeattleUnited States
| | - Libin Xu
- Department of Medicinal Chemistry, University of WashingtonSeattleUnited States
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Różdżyńska-Świątkowska A, Ciara E, Halat-Wolska P, Krajewska-Walasek M, Jezela-Stanek A. Anthropometric characteristics of 65 Polish Smith-Lemli-Opitz patients. J Appl Genet 2021; 62:469-475. [PMID: 33890232 DOI: 10.1007/s13353-021-00632-5] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/23/2021] [Accepted: 04/07/2021] [Indexed: 11/26/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) belongs to a group of multiple congenital anomaly/developmental delay disorders. Its primary cause lies in the defect in cholesterol biosynthesis-7-dehydrocholesterol reductase (DHCR7)-caused by pathogenic variants in the homonymous gene. Anthropometric anomalies, especially growth restriction and microcephaly, are among the most common physical manifestations of SLOS. There have been no studies analyzing the correlation between genotype, biochemical marker (7-dehydrocholesterol), and the birth and growth parameters for individuals with SLOS. This paper presents anthropometric data from the group of 65 Polish patients (aged 0.1 to 18 years) with Smith-Lemli-Opitz syndrome, with genotype and biochemical correlations for birth parameters, as well as growth in relation to molecular DHCR7 variants.
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Affiliation(s)
| | - E Ciara
- Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
| | - P Halat-Wolska
- Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
| | - M Krajewska-Walasek
- Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, Warsaw, Poland
| | - A Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, Warsaw, Poland.
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Abdel-Khalik J, Hearn T, Dickson AL, Crick PJ, Yutuc E, Austin-Muttitt K, Bigger BW, Morris AA, Shackleton CH, Clayton PT, Iida T, Sircar R, Rohatgi R, Marschall HU, Sjövall J, Björkhem I, Mullins JGL, Griffiths WJ, Wang Y. Bile acid biosynthesis in Smith-Lemli-Opitz syndrome bypassing cholesterol: Potential importance of pathway intermediates. J Steroid Biochem Mol Biol 2021; 206:105794. [PMID: 33246156 PMCID: PMC7816163 DOI: 10.1016/j.jsbmb.2020.105794] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022]
Abstract
Bile acids are the end products of cholesterol metabolism secreted into bile. They are essential for the absorption of lipids and lipid soluble compounds from the intestine. Here we have identified a series of unusual Δ5-unsaturated bile acids in plasma and urine of patients with Smith-Lemli-Opitz syndrome (SLOS), a defect in cholesterol biosynthesis resulting in elevated levels of 7-dehydrocholesterol (7-DHC), an immediate precursor of cholesterol. Using liquid chromatography - mass spectrometry (LC-MS) we have uncovered a pathway of bile acid biosynthesis in SLOS avoiding cholesterol starting with 7-DHC and proceeding through 7-oxo and 7β-hydroxy intermediates. This pathway also occurs to a minor extent in healthy humans, but elevated levels of pathway intermediates could be responsible for some of the features SLOS. The pathway is also active in SLOS affected pregnancies as revealed by analysis of amniotic fluid. Importantly, intermediates in the pathway, 25-hydroxy-7-oxocholesterol, (25R)26-hydroxy-7-oxocholesterol, 3β-hydroxy-7-oxocholest-5-en-(25R)26-oic acid and the analogous 7β-hydroxysterols are modulators of the activity of Smoothened (Smo), an oncoprotein that mediates Hedgehog (Hh) signalling across membranes during embryogenesis and in the regeneration of postembryonic tissue. Computational docking of the 7-oxo and 7β-hydroxy compounds to the extracellular cysteine rich domain of Smo reveals that they bind in the same groove as both 20S-hydroxycholesterol and cholesterol, known activators of the Hh pathway.
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Affiliation(s)
- Jonas Abdel-Khalik
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Thomas Hearn
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Alison L Dickson
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Peter J Crick
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Eylan Yutuc
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Karl Austin-Muttitt
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - Brian W Bigger
- Stem Cell & Neurotherapies, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, M13 9PT, UK
| | - Andrew A Morris
- Willink Unit, Manchester Centre for Genomic Medicine, Manchester University Hospitals, Manchester, M13 9WL, UK
| | - Cedric H Shackleton
- University of California San Francisco (UCSF) Benioff Children's Hospital, Oakland, CA 94609, USA
| | - Peter T Clayton
- Inborn Errors of Metabolism, Genetics and Genomic Medicine, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, UK
| | - Takashi Iida
- Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo, 156-8550, Japan
| | - Ria Sircar
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Rajat Rohatgi
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Hanns-Ulrich Marschall
- Department of Molecular and Clinical Medicine, University of Gothenburg, Sahlgrenska Academy, Institute of Medicine, Gothenburg, 41345, Sweden
| | - Jan Sjövall
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, 17177, Sweden
| | - Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Huddinge, 14186, Stockholm, Sweden
| | - Jonathan G L Mullins
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK
| | - William J Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK.
| | - Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, Wales, UK.
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Gao C, Duan J, Zhang P, Gao Y, Zhang Y, Wang Y, An S, Huang J. [Clinical and genetic analysis of a Chinese pedigree affected with Smith-Lemli-Opitz syndrome]. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 2020; 37:1272-1275. [PMID: 33179238 DOI: 10.3760/cma.j.cn511374-20190929-00502] [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: 06/11/2023]
Abstract
OBJECTIVE To explore the clinical phenotype and pathogenic variants in a Chinese pedigree affected with Smith-Lemli-Opitz syndrome. METHODS Peripheral blood samples were collected from five members, including two affected ones, from the pedigree for the extraction of genomic DNA. Whole exome sequencing was carried out, and candidate variants were verified by Sanger sequencing as well as reverse transcription sequencing at the RNA level. RESULTS The proband and another affected child from the pedigree showed mental retardation, dyskinesia, microcephaly, micrognathia, anteverted nares, and 2/3 toe syndactyly. The proband also had hypospadia, single upper incisor, and lower serum cholesterol level. Both children were found to harbor a paternally derived c.278C>T (p.T93M) variant and a maternally derived c.907G>A (p.G303R) variant of the DHCR7 gene. Both were known pathogenic mutations. CONCLUSION The compound heterozygous mutations of c.278C>T (p.T93M) and c.907G>A (p.G303R) of the DHCR7 gene probably underlay the disease in this pedigree. Above finding has enabled early diagnosis and treatment of Smith-Lemli-Opitz syndrome.
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Affiliation(s)
- Chao Gao
- Department of Rehabilitation Medicine, Children' Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, Henan 450018, China.
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Abstract
Stillbirth after 20 weeks gestation happens in 1 in 200 pregnancies and occurs more commonly than neonatal loss and sudden infant death syndrome (SIDs) combined. The stillbirth rate is several times greater in low as opposed to high-resource countries. However, among high-resource countries, although a lower overall stillbirth rate exists, there has been little change for several decades. Molecular genetic technologies are emerging as important contributors to our understanding of stillbirth. Initially, genetic etiologies included alterations in chromosome number or structure such as aneuploidy and microduplications and deletions. More recently, next-generation sequencing analysis in two genetic conditions, Smith Lemli Optiz Syndrome (SLOs) and the channelopathy disorders (such as long QT syndrome (LQTS)) provide examples into the association of pathogenic gene variants with stillbirth. Although these specific conditions individually account for only a small number of stillbirths, investigating these disorders provides a new and innovative approach for further understanding genetic contributors to adverse pregnancy outcomes. Our knowledge of the role of genetic disease as an etiology for stillbirth is elementary. Genomic interrogation of maternal-fetal genotypes, gene-gene, and genotype-environment interaction is lacking in stillbirth research. At the DNA sequence level, further investigation of variants of unknown significance is an opportunity for exploration of biologic pathways of importance to pregnancy loss. This review concentrates on SLO as an example of a single gene disorder with a high carrier but low affected liveborn proband rate. The channelopathy disorders are included as initial examples of genetic conditions with variable presentation including an association with sudden infant death syndrome. Highlighted are the challenges when numerous genes and variants are involved, and the task of assigning pathogenicity. The advantages and limitations of genetic evaluations are presented and avenues for further research considered.
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Affiliation(s)
- Louise Wilkins-Haug
- Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 01770, USA.
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Fliesler SJ, Xu L. Oxysterols and Retinal Degeneration in a Rat Model of Smith-Lemli-Opitz Syndrome: Implications for an Improved Therapeutic Intervention. Molecules 2018; 23:E2720. [PMID: 30360379 PMCID: PMC6222618 DOI: 10.3390/molecules23102720] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [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: 09/12/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 01/31/2023] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive human disease caused by mutations in the gene encoding 7-dehydrocholesterol (7DHC) reductase (DHCR7), resulting in abnormal accumulation of 7DHC and reduced levels of cholesterol in bodily tissues and fluids. A rat model of the disease has been created by treating normal rats with the DHCR7 inhibitor, AY9944, which causes progressive, irreversible retinal degeneration. Herein, we review the features of this disease model and the evidence linking 7DHC-derived oxysterols to the pathobiology of the disease, with particular emphasis on the associated retinal degeneration. A recent study has shown that treating the rat model with cholesterol plus suitable antioxidants completely prevents the retinal degeneration. These findings are discussed with regard to their translational implications for developing an improved therapeutic intervention for SLOS over the current standard of care.
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Affiliation(s)
- Steven J Fliesler
- Departments of Ophthalmology and Biochemistry and Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA.
- Research Service, VA Western NY Healthcare System, Buffalo, NY 14260, USA.
| | - Libin Xu
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA 98195, USA.
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Gibbins KJ, Reddy UM, Saade GR, Goldenberg RL, Dudley DJ, Parker CB, Thorsten V, Pinar H, Bukowski R, Hogue CJ, Silver RM. Smith-Lemli-Opitz Mutations in Unexplained Stillbirths. Am J Perinatol 2018; 35:936-939. [PMID: 29433144 PMCID: PMC6060008 DOI: 10.1055/s-0038-1626705] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive syndrome caused by a defect in cholesterol biosynthesis with mutations in 7-dehydrocholesterol reductase (DHCR7). A total of 3% of Caucasians carry DHCR7 mutations, theoretically resulting in a homozygote frequency of 1/4000. However, SLOS occurs in only 1/20,000 to 60,000 live births. Our objective was to assess DHCR7 mutations in unexplained stillbirths. STUDY DESIGN Prospective, multicenter, population-based case-control study of all stillbirths and a representative sample of live births enrolled in five geographic areas. Cases with stillbirth due to obstetric complications, infection, or aneuploidy, and those with poor quality deoxyribonucleic acid (DNA) were excluded. DNA was extracted from placental tissue stored at -80°C, and exons 3 to 9 of the DCHR7 gene were amplified, purified, and subjected to bidirectional sequencing to identify mutations. RESULTS One-hundred forty four stillbirths were unexplained and had adequate DNA for analysis. Nine stillbirths of 139 (6.5%) had a single mutation in one allele in coding exons 3 to 9 of DHCR7 (Table 1). One case (0.7%) was a compound heterozygote for mutations in exons 3 to 9 of DHCR7; this fetus had no clinical or histologic features of SLOS. CONCLUSION We detected SLOS mutations in only 0.7% of stillbirths. This does not support a strong association between unrecognized DHCR7 mutations and stillbirth.
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Affiliation(s)
| | - Uma M. Reddy
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland
| | | | | | | | | | | | - Halit Pinar
- The Warren Alpert Medical School of Brown University, Providence, Rhode Island
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Ramachandra Rao S, Pfeffer BA, Más Gómez N, Skelton LA, Keiko U, Sparrow JR, Rowsam AM, Mitchell CH, Fliesler SJ. Compromised phagosome maturation underlies RPE pathology in cell culture and whole animal models of Smith-Lemli-Opitz Syndrome. Autophagy 2018; 14:1796-1817. [PMID: 29979914 PMCID: PMC6135634 DOI: 10.1080/15548627.2018.1490851] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [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: 08/10/2017] [Revised: 05/25/2018] [Accepted: 06/11/2018] [Indexed: 12/27/2022] Open
Abstract
Treatment of rats with the cholesterol pathway inhibitor AY9944 produces an animal model of Smith-Lemli-Opitz syndrome (SLOS), an autosomal recessive disease caused by defective cholesterol synthesis. This SLOS rat model undergoes progressive and irreversible degeneration of the neural retina, with associated pathological features of the retinal pigmented epithelium (RPE). Here, we provide further insights into the mechanism involved in the RPE pathology. In the SLOS rat model, markedly increased RPE apical autofluorescence is observed, compared to untreated animals, which correlates with increased levels of A2E and other bisretinoids. Utilizing cultured human induced pluripotent stem cell (iPSC)- derived SLOS RPE cells, we found significantly elevated steady-state levels of 7-dehydrocholesterol (7DHC) and decreased cholesterol levels (key biochemical hallmarks of SLOS). Western blot analysis revealed altered levels of the macroautophagy/autophagy markers MAP1LC3B-II and SQSTM1/p62, and build-up of ubiquitinated proteins. Accumulation of immature autophagosomes was accompanied by inefficient degradation of phagocytized, exogenously supplied retinal rod outer segments (as evidenced by persistence of the C-terminal 1D4 epitope of RHO [rhodopsin]) in SLOS RPE compared to iPSC-derived normal human control. SLOS RPE cells exhibited lysosomal pH levels and CTSD activity within normal physiological limits, thus discounting the involvement of perturbed lysosomal function. Furthermore, 1D4-positive phagosomes that accumulated in the RPE in both pharmacological and genetic rodent models of SLOS failed to fuse with lysosomes. Taken together, these observations suggest that defective phagosome maturation underlies the observed RPE pathology. The potential relevance of these findings to SLOS and the requirement of cholesterol for phagosome maturation are discussed.
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Affiliation(s)
- Sriganesh Ramachandra Rao
- Departments of Ophthalmology (Ross Eye Institute) and Biochemistry, Jacobs School of Medicine and Biomedical Sciences, SUNY-University at Buffalo, Buffalo, NY, USA
- SUNY Eye Institute, Buffalo, NY, USA
- Research Service, VA Western NY Healthcare System, Buffalo, NY, USA
| | - Bruce A. Pfeffer
- Departments of Ophthalmology (Ross Eye Institute) and Biochemistry, Jacobs School of Medicine and Biomedical Sciences, SUNY-University at Buffalo, Buffalo, NY, USA
- SUNY Eye Institute, Buffalo, NY, USA
- Research Service, VA Western NY Healthcare System, Buffalo, NY, USA
| | - Néstor Más Gómez
- Department of Anatomy & Cell Biology, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA, USA
| | - Lara A. Skelton
- Departments of Ophthalmology (Ross Eye Institute) and Biochemistry, Jacobs School of Medicine and Biomedical Sciences, SUNY-University at Buffalo, Buffalo, NY, USA
- SUNY Eye Institute, Buffalo, NY, USA
- Research Service, VA Western NY Healthcare System, Buffalo, NY, USA
| | - Ueda Keiko
- Departments of Ophthalmology (Harkness Eye Institute) and Pathology & Cell Biology, Columbia University, College of Physicians & Surgeons, NY, NY, USA
| | - Janet R. Sparrow
- Departments of Ophthalmology (Harkness Eye Institute) and Pathology & Cell Biology, Columbia University, College of Physicians & Surgeons, NY, NY, USA
| | - Aryn M. Rowsam
- Departments of Ophthalmology (Ross Eye Institute) and Biochemistry, Jacobs School of Medicine and Biomedical Sciences, SUNY-University at Buffalo, Buffalo, NY, USA
- SUNY Eye Institute, Buffalo, NY, USA
- Research Service, VA Western NY Healthcare System, Buffalo, NY, USA
| | - Claire H. Mitchell
- Department of Anatomy & Cell Biology, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA, USA
| | - Steven J. Fliesler
- Departments of Ophthalmology (Ross Eye Institute) and Biochemistry, Jacobs School of Medicine and Biomedical Sciences, SUNY-University at Buffalo, Buffalo, NY, USA
- SUNY Eye Institute, Buffalo, NY, USA
- Research Service, VA Western NY Healthcare System, Buffalo, NY, USA
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12
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Abstract
PURPOSE OF REVIEW To update researchers of recently discovered metabolites of cholesterol and of its precursors and to suggest relevant metabolic pathways. RECENT FINDINGS Patients suffering from inborn errors of sterol biosynthesis, transport and metabolism display unusual metabolic pathways, which may be major routes in the diseased state but minor in the healthy individual. Although quantitatively minor, these pathways may still be important in healthy individuals. Four inborn errors of metabolism, Smith-Lemli-Opitz syndrome, cerebrotendinous xanthomatosis and Niemann Pick disease types B (NPB) and C (NPC) result from mutations in different genes but can generate elevated levels of the same sterol metabolite, 7-oxocholesterol, in plasma. How this molecule is metabolized further is of great interest as its metabolites may have an important role in embryonic development. A second metabolite, abundant in NPC and NPB diseases, cholestane-3β,5α,6β-triol (3β,5α,6β-triol), has recently been shown to be metabolized to the corresponding bile acid, 3β,5α,6β-trihydroxycholanoic acid, providing a diagnostic marker in plasma. The origin of cholestane-3β,5α,6β-triol is likely to be 3β-hydroxycholestan-5,6-epoxide, which can alternatively be metabolized to the tumour suppressor dendrogenin A (DDA). In breast tumours, DDA levels are found to be decreased compared with normal tissues linking sterol metabolism to cancer. SUMMARY Unusual sterol metabolites and pathways may not only provide markers of disease, but also clues towards cause and treatment.
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Affiliation(s)
- Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, UK
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13
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Peng Y, Myers R, Zhang W, Alexov E. Computational Investigation of the Missense Mutations in DHCR7 Gene Associated with Smith-Lemli-Opitz Syndrome. Int J Mol Sci 2018; 19:E141. [PMID: 29300326 PMCID: PMC5796090 DOI: 10.3390/ijms19010141] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [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: 11/16/2017] [Revised: 12/29/2017] [Accepted: 12/30/2017] [Indexed: 12/25/2022] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a cholesterol synthesis disorder characterized by physical, mental, and behavioral symptoms. It is caused by mutations in 7-dehydroxycholesterolreductase gene (DHCR7) encoding DHCR7 protein, which is the rate-limiting enzyme in the cholesterol synthesis pathway. Here we demonstrate that pathogenic mutations in DHCR7 protein are located either within the transmembrane region or are near the ligand-binding site, and are highly conserved among species. In contrast, non-pathogenic mutations observed in the general population are located outside the transmembrane region and have different effects on the conformational dynamics of DHCR7. All together, these observations suggest that the non-classified mutation R228Q is pathogenic. Our analyses indicate that pathogenic effects may affect protein stability and dynamics and alter the binding affinity and flexibility of the binding site.
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Affiliation(s)
- Yunhui Peng
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29630, USA.
| | - Rebecca Myers
- Department of Healthcare Genetics, Clemson University, Clemson, SC 29630, USA.
| | - Wenxing Zhang
- Department of Chemistry, Clemson University, Clemson, SC 29630, USA.
| | - Emil Alexov
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29630, USA.
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14
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Eroglu Y, Nguyen-Driver M, Steiner RD, Merkens L, Merkens M, Roullet JB, Elias E, Sarphare G, Porter FD, Li C, Tierney E, Nowaczyk MJ, Freeman KA. Normal IQ is possible in Smith-Lemli-Opitz syndrome. Am J Med Genet A 2017; 173:2097-2100. [PMID: 28349652 PMCID: PMC6016830 DOI: 10.1002/ajmg.a.38125] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/28/2016] [Accepted: 12/08/2016] [Indexed: 12/19/2022]
Abstract
Children with Smith-Lemli-Opitz syndrome (SLOS) are typically reported to have moderate to severe intellectual disability. This study aims to determine whether normal cognitive function is possible in this population and to describe clinical, biochemical and molecular characteristics of children with SLOS and normal intelligent quotient (IQ). The study included children with SLOS who underwent cognitive testing in four centers. All children with at least one IQ composite score above 80 were included in the study. Six girls, three boys with SLOS were found to have normal or low-normal IQ in a cohort of 145 children with SLOS. Major/multiple organ anomalies and low serum cholesterol levels were uncommon. No correlation with IQ and genotype was evident and no specific developmental profile were observed. Thus, normal or low-normal cognitive function is possible in SLOS. Further studies are needed to elucidate factors contributing to normal or low-normal cognitive function in children with SLOS.
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Affiliation(s)
- Yasemen Eroglu
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
| | - Mina Nguyen-Driver
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
- Institute on Development and Disability, Oregon Health and Science University, Portland, Oregon
| | - Robert D Steiner
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
- Institute on Development and Disability, Oregon Health and Science University, Portland, Oregon
- Department of Molecular and Medical Genetics, Institute on Development and Disability, Doernbecher Children's Hospital, Portland, Oregon
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin
| | - Louise Merkens
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
| | - Mark Merkens
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
| | - Jean-Baptiste Roullet
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
- Department of Experimental and Systems Pharmacology, College of Pharmacy, Washington State University, Spokane, Washington
| | - Ellen Elias
- Children's Hospital Colorado, Aurora, Colorado
| | | | - Forbes D Porter
- Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institution of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Chumei Li
- Department of Pathology and Medicine, and Pediatrics, McMaster University, Hamilton, ON, Canada
| | | | - Małgorzata J Nowaczyk
- Department of Pathology and Medicine, and Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Kurt A Freeman
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
- Institute on Development and Disability, Oregon Health and Science University, Portland, Oregon
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15
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Kelly MN, Tuli SY, Tuli SS, Stern MA, Giordano BP. Brothers with Smith-Lemli-Opitz syndrome. J Pediatr Health Care 2015; 29:97-103. [PMID: 24954735 DOI: 10.1016/j.pedhc.2014.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/10/2014] [Accepted: 04/24/2014] [Indexed: 12/13/2022]
Abstract
Abnormal cholesterol metabolism is the cause of SLOS, with low cholesterol levels and elevated levels of cholesterol precursors thought to contribute to the clinical findings in this syndrome. Management of SLOS involves early intervention with appropriate therapies for identified disabilities, genetic counseling for families, nutritional consultations, educational interventions, and behavioral management. Although no randomized dietary studies have been conducted, cholesterol supplementation continues to be a common recommendation for persons with SLOS, because it may result in clinical improvement and has few adverse effects (Nowaczyk, 2013). Even with early detection and treatment (e.g., sibling B in this case report), persons with SLOS often have significant behavioral issues and cognitive and developmental delays that require a team approach by parents, educators, specialists, and primary care providers.
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16
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Natesan SA, Handyside AH, Thornhill AR, Ottolini CS, Sage K, Summers MC, Konstantinidis M, Wells D, Griffin DK. Live birth after PGD with confirmation by a comprehensive approach (karyomapping) for simultaneous detection of monogenic and chromosomal disorders. Reprod Biomed Online 2014; 29:600-5. [PMID: 25154779 DOI: 10.1016/j.rbmo.2014.07.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 11/20/2022]
Abstract
Preimplantation genetic diagnosis (PGD) for monogenic disorders has the drawback of time and cost associated with tailoring a specific test for each couple, disorder, or both. The inability of any single assay to detect the monogenic disorder in question and simultaneously the chromosomal complement of the embryo also limits its application as separate tests may need to be carried out on the amplified material. The first clinical use of a novel approach ('karyomapping') was designed to circumvent this problem. In this example, karyomapping was used to confirm the results of an existing PGD case detecting both chromosomal abnormalities and a monogenic disorder (Smith-Lemli-Opitz [SLO] syndrome) simultaneously. The family underwent IVF, ICSI and PGD, and both polar body and cleavage stage biopsy were carried out. Following whole genome amplification, array comparative genomic hybridisation of the polar bodies and minisequencing and STR analysis of single blastomeres were used to diagnose maternal aneuploidies and SLO status, respectively. This was confirmed, by karyomapping. Unlike standard PGD, karyomapping required no a-priori test development. A singleton pregnancy and live birth, unaffected with SLO syndrome and with no chromosome abnormality, ensued. Karyomapping is potentially capable of detecting a wide spectrum of monogenic and chromosome disorders and, in this context, can be considered a comprehensive approach to PGD.
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Affiliation(s)
| | - Alan H Handyside
- The London Bridge Fertility Gynaecology and Genetics Centre, London, SE1 9RY, UK; School of Biosciences, University of Kent, CT2 7NJ, Canterbury, UK; Illumina, CPC4, Capital Park, Fulbourn, Cambridge, CB21 5XE, UK
| | - Alan R Thornhill
- The London Bridge Fertility Gynaecology and Genetics Centre, London, SE1 9RY, UK; School of Biosciences, University of Kent, CT2 7NJ, Canterbury, UK; Illumina, CPC4, Capital Park, Fulbourn, Cambridge, CB21 5XE, UK
| | - Christian S Ottolini
- The London Bridge Fertility Gynaecology and Genetics Centre, London, SE1 9RY, UK; School of Biosciences, University of Kent, CT2 7NJ, Canterbury, UK
| | - Karen Sage
- The London Bridge Fertility Gynaecology and Genetics Centre, London, SE1 9RY, UK
| | - Michael C Summers
- The London Bridge Fertility Gynaecology and Genetics Centre, London, SE1 9RY, UK; School of Biosciences, University of Kent, CT2 7NJ, Canterbury, UK
| | - Michalis Konstantinidis
- Institute of Reproductive Sciences, University of Oxford, Oxford Business Park North, Cowley, Oxford, Oxfordshire, OX4 2HW, UK
| | - Dagan Wells
- Institute of Reproductive Sciences, University of Oxford, Oxford Business Park North, Cowley, Oxford, Oxfordshire, OX4 2HW, UK
| | - Darren K Griffin
- School of Biosciences, University of Kent, CT2 7NJ, Canterbury, UK.
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17
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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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18
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De Clemente V, Vitiello G, Imperati F, Romano A, Parente I, Rosa M, Pascarella A, Parenti G, Del Giudice E. Smith Lemli-Opitz syndrome: a contribution to the delineation of a cognitive/behavioral phenotype. Minerva Pediatr 2013; 65:61-69. [PMID: 23422574] [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: 06/01/2023]
Abstract
AIM Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive congenital malformation syndrome caused by an inborn error of cholesterol biosynthesis. The incidence is around 1:20000-1:70000. SLOS phenotype is very broad: severe phenotypes show exitus in perinatal period while milder phenotypes only show behavioral and learning problems. The purpose of this study is to further contribute to the delineation of a cognitive and behavioral phenotype in SLOS. METHODS Nine patients with SLOS aged between 22 months and 25 years have been followed at the Department of Pediatrics, University of Naples "Federico II" for 2 years. A neuropsychologic study has been carried out in order to assess motor development, adaptive skills, social behavior, communication and language, temperament, aggressive behavior, symptoms typical of autism spectrum disorders (ASDs). RESULTS The overall assessment of cognitive/behavioral phenotype showed severe / profound mental retardation in most of them (8/9) with a quite homogeneous neuropsychological profile. The language area was deficient both in expressive and receptive skills. Adaptive skills were in line with mental development. The presence of behavior problems (self-injury and stereotypies) was detected in 6 patients. The study of temperament showed a trend towards a sedentary lifestyle, lack of inhibition against novelty and danger, and reduced interest in the stimuli. None of our patients could be diagnosed as having ASDs. CONCLUSION Although a specific behavioral phenotype for SLOS has gained support in the literature, we believe that many of the features described in individuals with SLOS are common to other mental retardation syndromes.
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Affiliation(s)
- V De Clemente
- Department of Pediatrics, University of Naples Federico II, Naples, Italy
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19
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Korade Z, Xu L, Mirnics K, Porter NA. Lipid biomarkers of oxidative stress in a genetic mouse model of Smith-Lemli-Opitz syndrome. J Inherit Metab Dis 2013; 36:113-22. [PMID: 22718275 PMCID: PMC3674764 DOI: 10.1007/s10545-012-9504-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [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: 03/13/2012] [Revised: 05/09/2012] [Accepted: 05/20/2012] [Indexed: 02/01/2023]
Abstract
7-Dehydrocholesterol (7-DHC) accumulates in tissues and fluids of patients with Smith-Lemli-Opitz syndrome (SLOS), which is caused by mutations in the gene encoding 3β-hydroxysterol-Δ(7)-reductase (DHCR7). We recently reported that 7-DHC is the most reactive lipid molecule toward free radical oxidation (lipid peroxidation) and 14 oxysterols have been identified as products of oxidation of 7-DHC in solution. As the high oxidizability of 7-DHC may lead to systemic oxidative stress in SLOS patients, we report here lipid biomarkers of oxidative stress in a Dhcr7-KO mouse model of SLOS, including oxysterols, isoprostanes (IsoPs), and neuroprostanes (NeuroPs) that are formed from the oxidation of 7-DHC, arachidonic acid and docosahexaenoic acid, respectively. In addition to a previously described oxysterol, 3β,5α-dihydroxycholest-7-en-6-one (DHCEO), we provide evidence for the chemical structures of three new oxysterols in the brain and/or liver tissue of Dhcr7-KO mice, two of which were quantified. We find that levels of IsoPs and NeuroPs are also elevated in brain and/or liver tissues of Dhcr7-KO mice relative to matching WT mice. While IsoPs and NeuroPs have been established as a reliable measurement of lipid peroxidation and oxidative stress in vivo, we show that in this genetic SLOS mouse model, 7-DHC-derived oxysterols are present at much higher levels than IsoPs and NeuroPs and thus are better markers of lipid oxidation and related oxidative stress.
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Affiliation(s)
- Zeljka Korade
- Department of Psychiatry and Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN 37235, USA
| | - Libin Xu
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Nashville, TN 37235, USA
| | - Karoly Mirnics
- Department of Psychiatry and Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN 37235, USA
| | - Ned A. Porter
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Nashville, TN 37235, USA. Department of Chemistry, 7962 Stevenson Center, Vanderbilt University, Nashville, TN 37235, USA
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20
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Xu L, Mirnics K, Bowman AB, Liu W, Da J, Porter NA, Korade Z. DHCEO accumulation is a critical mediator of pathophysiology in a Smith-Lemli-Opitz syndrome model. Neurobiol Dis 2011; 45:923-9. [PMID: 22182693 DOI: 10.1016/j.nbd.2011.12.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [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: 08/09/2011] [Revised: 10/25/2011] [Accepted: 12/04/2011] [Indexed: 11/19/2022] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an inborn error of metabolism caused by defective cholesterol biosynthesis. Mutations within the gene encoding 7-dehydrocholesterol reductase (DHCR7), the last enzyme in the pathway, lead to the accumulation of 7-dehydrocholesterol (7-DHC) in the brain tissue and blood of the SLOS patients. The objective of this study was to determine the consequences of the accumulation of an immediate cholesterol precursor, 7-DHC and its oxysterol metabolite, 3β,5α-dihydroxycholest-7-en-6-one (DHCEO), in the brain tissue of Dhcr7-KO mouse, a model for SLOS. We found that cholesterol, 7-DHC and DHCEO show region-specific distribution, suggesting that the midbrain and the cortex are the primary sites of vulnerability. We also report that neurons are ten fold more susceptible to a 7-DHC-derived oxysterol mixture than glial cells, and that DHCEO accelerates differentiation and arborization of cortical neurons. The overall results suggest that 7-DHC oxidative metabolites are critical contributors to altered neural development in SLOS. The future studies will test if antioxidant supplementation will ameliorate some of the clinical symptoms associated with this devastating disease.
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Affiliation(s)
- Libin Xu
- Department of Chemistry and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA
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21
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Abstract
Data obtained from recent studies in humans, rodents, and cell culture demonstrate that circulating maternal cholesterol can be transported to the fetus. The two major cell types responsible for the transport are trophoblasts and endothelial cells of the fetoplacental vasculature. Maternal lipoprotein-cholesterol is initially taken up by trophoblasts via receptor-mediated and receptor-independent processes, is transported by any number of the sterol transport proteins expressed by cells, and is effluxed or secreted out of the basal side via protein-mediated processes or by aqueous diffusion. This cholesterol is then taken up by the endothelium and effluxed to acceptors within the fetal circulation. The ability to manipulate the mass of maternal cholesterol that is taken up by the placenta and crosses to the fetus could positively impact development of fetuses affected with the Smith-Lemli-Opitz Syndrome (SLOS) that have reduced ability to synthesize cholesterol and possibly impact growth of fetuses unaffected by SLOS but with low birthweights.
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Affiliation(s)
- L A Woollett
- University of Cincinnati, Metabolic Diseases Institute, Department of Pathology, Cincinnati, OH 45236-507, USA.
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22
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Jezela-Stanek A, Ciara E, Małunowicz E, Chrzanowska K, Latos-Bieleńska A, Krajewska-Walasek M. Differences between predicted and established diagnoses of Smith-Lemli-Opitz syndrome in the Polish population: underdiagnosis or loss of affected fetuses? J Inherit Metab Dis 2010; 33 Suppl 3:S241-8. [PMID: 20556518 DOI: 10.1007/s10545-010-9132-4] [Citation(s) in RCA: 8] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 03/26/2010] [Accepted: 05/14/2010] [Indexed: 10/19/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a metabolic disorder in which an error in cholesterol biosynthesis results in congenital anomalies/mental deficits. The results of our previous newborn screening, based on the carrier frequency of the two most common SLOS-causing mutations in Poland (p.W151X and p.V326L), would make SLOS one of the most frequent recessive disorders in our country (with an incidence of 1:2,300 - 1:3,937). This prompted us to carry out a 3-year (2006-2008) national surveillance program in which about 2,000 physicians were asked to identify potential SLOS patients pre- and postnatally based on clinical identification forms. The incidence of SLOS in Poland was estimated to be from 1:60,941 to 1:105,395 (1: 83,168 ± 22,227) live births, and its 3-year prevalence 1:866,273 ± 16,242. The mean carrier frequency was calculated to be from 1:123 to 1:165. The notable discrepancy between our previous carrier newborn screening and these prospective data may result from reduced fertility in SLOS carriers, intrauterine death of affected fetuses, or underdiagnosis in postnatal life. Since we did not notice significant data supporting the first two aspects, our study may support the suggestion that screening for the most frequent DHCR7 alleles does not reflect the true disease rates in the Polish population. Hence, further studies in which maternal urinary steroids (7-dehydroestriol/estriol and 8-dehydropregnanetriol/pregnanetriol ratios) would serve as screening markers in early pregnancies may be justified.
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Affiliation(s)
- Aleksandra Jezela-Stanek
- Department of Medical Genetics, The Children's Memorial Health Institute, Aleja Dzieci Polskich 20, 04-736 Warsaw, Poland.
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23
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Serra M, Matabosch X, Ying L, Watson G, Shackleton C. Hair and skin sterols in normal mice and those with deficient dehydrosterol reductase (DHCR7), the enzyme associated with Smith-Lemli-Opitz syndrome. J Steroid Biochem Mol Biol 2010; 122:318-25. [PMID: 20804844 PMCID: PMC2964438 DOI: 10.1016/j.jsbmb.2010.08.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [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: 06/04/2010] [Revised: 08/19/2010] [Accepted: 08/20/2010] [Indexed: 12/20/2022]
Abstract
Our recent studies have focused on cholesterol synthesis in mouse models for 7-dehydrosterolreductase (DHCR7) deficiency, also known as Smith-Lemli-Opitz syndrome. Investigations of such mutants have relied on tissue and blood levels of the cholesterol precursor 7-dehydrocholesterol (7DHC) and its 8-dehydro isomer. In this investigation by gas chromatography/mass spectrometry (GC/MS) we have identified and quantified cholesterol and its precursors (7DHC, desmosterol, lathosterol, lanosterol and cholest-7,24-dien-3β-ol) in mouse hair. The components were characterized and their concentrations were compared to those found in mouse skin and serum. Hair appeared unique in that desmosterol was a major sterol component, almost matching in concentration cholesterol itself. In DHCR7 deficient mice, dehydrodesmosterol (DHD) was the dominant hair Δ(7) sterol. Mutant mouse hair had much higher concentrations of 7-dehydrosterols relative to cholesterol than did serum or tissue at all ages studied. The 7DHC/C ratio in hair was typically about sevenfold the value in serum or skin and the DHD/D ratio was 100× that of the serum 7DHC/C ratio. Mutant mice compensate for their DHCR7 deficiency with maturity, and the tissue and blood 7DHC/C become close to normal. That hair retains high relative concentrations of the dehydro precursors suggests that the apparent up-regulation of Dhcr7 seen in liver is slower to develop at the site of hair cholesterol synthesis.
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Affiliation(s)
- Montserrat Serra
- Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
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24
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Abstract
Disorders of androgen production can occur in all steps of testosterone biosynthesis and secretion carried out by the foetal Leydig cells as well as in the conversion of testosterone into dihydrotestosterone (DHT). The differentiation of Leydig cells from mesenchymal cells is the first walk for testosterone production. In 46,XY disorders of sex development (DSDs) due to Leydig cell hypoplasia, there is a failure in intrauterine and postnatal virilisation due to the paucity of interstitial Leydig cells to secrete testosterone. Enzymatic defects which impair the normal synthesis of testosterone from cholesterol and the conversion of testosterone to its active metabolite DHT are other causes of DSD due to impaired androgen production. Mutations in the genes that codify the enzymes acting in the steps from cholesterol to DHT have been identified in affected patients. Patients with 46,XY DSD secondary to defects in androgen production show a variable phenotype, strongly depending of the specific mutated gene. Often, these conditions are detected at birth due to the ambiguity of external genitalia but, in several patients, the extremely undervirilised genitalia postpone the diagnosis until late childhood or even adulthood. These patients should receive long-term care provided by multidisciplinary teams with experience in this clinical management.
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Affiliation(s)
- Berenice B Mendonca
- Hospital das Clinicas, Faculdade de Medicina da Universidade de Sao Paulo, Sao Paulo, Brazil.
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25
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Pineda-Alvarez DE, Dubourg C, David V, Roessler E, Muenke M. Current recommendations for the molecular evaluation of newly diagnosed holoprosencephaly patients. Am J Med Genet C Semin Med Genet 2010; 154C:93-101. [PMID: 20104604 PMCID: PMC2815008 DOI: 10.1002/ajmg.c.30253] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Holoprosencephaly (HPE) is the most common structural malformation of the developing forebrain in humans and is typically characterized by different degrees of hemispheric separation that are often accompanied by similarly variable degrees of craniofacial and midline anomalies. HPE is a classic example of a complex genetic trait with "pseudo"-autosomal dominant transmission showing incomplete penetrance and variable expressivity. Clinical suspicion of HPE is typically based upon compatible craniofacial findings, the presence of developmental delay or seizures, or specific endocrinological abnormalities, and is then followed up by confirmation with brain imaging. Once a clinical diagnosis is made, a thorough genetic evaluation is necessary. This usually includes analysis of chromosomes by high-resolution karyotyping, clinical assessment to rule-out well recognized syndromes that are associated with HPE (e.g., Pallister-Hall syndrome, Smith-Lemli-Opitz syndrome and others), and molecular studies of the most common HPE associated genes (e.g., SHH, ZIC2 and SIX3). In this review, we provide current step-by-step recommendations that are medically indicated for the genetic evaluation of patients with newly diagnosed HPE. Moreover, we provide a brief review of several available methods used in molecular diagnostics of HPE and describe the advantages and limitations of both currently available and future tests as they relate to high throughput screening, cost, and the results that they may provide.
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Affiliation(s)
| | - Christèle Dubourg
- Université de Rennes 1, Faculté de Médecine - UMR 6061 CNRS, IFR140 GFAS, Rennes, France
- CHU Pontchaillou - Laboratoire de Génétique Moléculaire, Rennes, France
| | - Véronique David
- Université de Rennes, 35042 - CNRS Génétique et Développement, Rennes, France
| | - Erich Roessler
- National Human Genome Research Institute - Medical Genetics Branch, Bethesda, Maryland, USA
| | - Maximilian Muenke
- National Human Genome Research Institute - Medical Genetics Branch, Bethesda, Maryland, USA
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26
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Ko JS, Choi BS, Seo JK, Shin JY, Chae JH, Kang GH, Lee R, Ki CS, Kim JW. A novel DHCR7 mutation in a Smith-Lemli-Opitz syndrome infant presenting with neonatal cholestasis. J Korean Med Sci 2010; 25:159-62. [PMID: 20052364 PMCID: PMC2799999 DOI: 10.3346/jkms.2010.25.1.159] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 08/18/2008] [Indexed: 11/20/2022] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive malformation syndrome caused by a defect in cholesterol biosynthesis. The incidence is very low in Asians and only one case has been reported in Korea thus far. Recently, we found an infant with neonatal cholestasis. He had microcephaly, ambiguous genitalia, cleft palate, syndactyly of toes, patent ductus arteriosus and hypertrophic pyloric stenosis. The serum cholesterol was decreased and serum 7-dehydrocholesterol was markedly elevated. Genetic analysis of the DHCR7 gene identified a novel missense mutation (Pro227Ser) as well as a known mutation (Gly303Arg) previously identified in a Japanese patient with SLOS. Although rare in Korea, SLOS should be considered in the differential diagnosis of neonatal cholestasis, especially in patients with multiple congenital anomalies and low serum cholesterol levels.
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Affiliation(s)
- Jae Sung Ko
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Byung Sam Choi
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Jeong Kee Seo
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Jee Yeon Shin
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Jong Hee Chae
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Gyeong Hoon Kang
- Department of Pathology, Seoul National University College of Medicine, Seoul, Korea
| | - Ran Lee
- Department of Pediatrics, Kunkuk University School of Medicine, Seoul, Korea
| | - Chang-Seok Ki
- Department of Laboratory Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jong-Won Kim
- Department of Laboratory Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea
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Lauda-Swieciak A, Przybył B, Moszczyńska K, Skórczewski J, Lach J, Szułczyński J, Ludwikowski G, Dubiel M. [Prenatal diagnosis of Smith-Lemli-Opitz syndrome--case report]. Ginekol Pol 2009; 80:778-781. [PMID: 19943544] [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: 05/28/2023] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a hereditary, autosomal recessive abnormality of cholesterol metabolism, leading to malformations of multiple organs. It is probably one of the most frequent metabolic disorders but variable clinical presentation makes the diagnosis of the syndrome difficult. The authors of the following work present a case report of prenatal diagnosis of SLOS in fetus with malformations of multiple organs and negative family history.
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Affiliation(s)
- Anna Lauda-Swieciak
- Oddział Ginekologii, Połoznictwa i Patologii Ciazy Wielospecjalistycznego Szpitala Miejskiego im. E. Warmińskiego w Bydgoszczy
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28
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Matabosch X, Rahman M, Hughes B, Patel SB, Watson G, Shackleton C. Steroid production and excretion by the pregnant mouse, particularly in relation to pregnancies with fetuses deficient in Delta7-sterol reductase (Dhcr7), the enzyme associated with Smith-Lemli-Opitz syndrome. J Steroid Biochem Mol Biol 2009; 116:61-70. [PMID: 19406241 PMCID: PMC2929956 DOI: 10.1016/j.jsbmb.2009.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [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: 11/29/2008] [Revised: 04/21/2009] [Accepted: 04/21/2009] [Indexed: 11/26/2022]
Abstract
This study has shown that the mouse has a great increase in steroid production during pregnancy in similar fashion to the human. Many steroids were provisionally identified in maternal urine of the wild-type mouse. The major progesterone metabolites appear to be hydroxylated pregnanolones, particularly with hydroxyl groups in the 16alpha position. Rather than estriol being the major end-product of feto-placental steroid synthesis as in the human, the pregnant mouse produces and excretes large amounts of androgen metabolites, ranging in polarity from androstanetriols to androstanepentols. These steroids have 15alpha- or 18-hydroxyl groups with additional hydroxylation at uncharacterized positions. From metabolite data the peak of pregnancy progesterone production appears to be between 7.5 and 14.5 gestational days, while for C(19) metabolites peak excretion is later. The starting-point of the studies was to study pregnancy steroid production by a mouse model for Smith-Lemli-Opitz syndrome, 7-dehydrosterol reductase (DHCR7) deficiency. In human pregnancies with DHCR7 deficient fetuses large amounts of 7- and 8-dehydrosteroids are excreted, products secondary to high fetal 7- and 8-dehydrocholesterol (DHC) accumulation. This agrees with existing evidence that human feto-placental steroid synthesis utilizes little maternal cholesterol as precursor. In contrast, this study has shown that pregnant mice carrying dhcr7 deficient fetuses with relatively high DHC production had essentially undetectable maternal excretions of steroids with Delta(7)- and Delta(8)-unsaturation. As mutant mouse mothers have essentially normal cholesterol production (little or no DHC build-up), this suggests maternal cholesterol is primarily utilized for pregnancy steroid synthesis in the mouse.
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Affiliation(s)
- Xavier Matabosch
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way Oakland, 94609, California
| | - Mahbuba Rahman
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way Oakland, 94609, California
| | - Beverly Hughes
- Institute of Biomedical Research, University of Birmingham, Wolfson Drive, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Shailendra B. Patel
- Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, 53226, Wisconsin
| | - Gordon Watson
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way Oakland, 94609, California
| | - Cedric Shackleton
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way Oakland, 94609, California
- Institute of Biomedical Research, University of Birmingham, Wolfson Drive, Edgbaston, Birmingham, B15 2TT, United Kingdom
- Address for correspondence:, Dr Cedric Shackleton, Children's Hospital Oakland Research Institute, 5700 Martin Luther King Way, Oakland, Ca 94609, Tel 510 450 7660, Fax 510 450 7910,
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29
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Kolejáková K, Petrovic R, Futas J, Turcáni P, Durovcíková D, Chandoga J. Spectrum of DHCR7 mutations in Slovak patients with Smith-Lemli-Opitz syndrome and detection of common mutations by PCR-based assays. Gen Physiol Biophys 2009; 28:8-15. [PMID: 19390132] [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: 05/27/2023]
Abstract
The Smith-Lemli-Opitz syndrome (SLOS), an autosomal recessive disorder associated with multiple developmental malformations, is caused by a large spectrum of mutations in the DHCR7 gene. Mutations in the DHCR7 gene lead to a 7-dehydrocholesterol reductase deficiency, which is the final enzyme in the pathway of the cholesterol biosynthesis. Reduced cholesterol levels and elevated concentrations of its precursor 7-dehydrocholesterol in plasma and tissues are the major biochemical hallmarks of this disorder. In all patients a biochemical analysis of blood sterols using the gas chromatography/mass spectrometry was performed to confirm the clinical diagnosis of SLOS. We have also determined the mutational spectrum of DHCR7 gene in 17 Slovak patients. We identified six different mutations: nonsense mutation W151X and missense mutations V326L, L109P, G410S, R352Q, Y432C. Mutations W151X and V326L accounted for 76% of the SLOS alleles in Slovak population. The Slovak mutational spectrum is similar to that observed in other Central European countries. We also report simple polymerase chain reaction (PCR)-based assays that allow efficient and rapid mutation analysis.
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Affiliation(s)
- Katarína Kolejáková
- Centre of Medical Genetics, University Hospital, Mickiewiczova 13, 813 69 Bratislava, Slovakia.
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Rakheja D, Boriack RL. Precholesterol sterols accumulate in lipid rafts of patients with Smith-Lemli-Opitz syndrome and X-linked dominant chondrodysplasia punctata. Pediatr Dev Pathol 2008; 11:128-32. [PMID: 17378665 DOI: 10.2350/06-10-0179.1] [Citation(s) in RCA: 13] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2006] [Accepted: 02/19/2007] [Indexed: 12/28/2022]
Abstract
Systemic fetal dysmorphogenesis in disorders of postsqualene cholesterol biosynthesis is thought to be caused by disruption of Hedgehog signaling. Because precholesterol sterols such as 7-dehydrocholesterol and lathosterol can replace cholesterol in the activation of Hedgehog proteins, it is currently believed that cholesterol deficiency-related Hedgehog signaling block occurs further downstream, probably at the level of Smoothened. Experimentally, such a block in Hedgehog signaling occurs at sterol levels of <40 mug/mg protein. Recently, we studied autopsy material from 2 infants with fatal cholesterol biosynthetic disorders (Smith-Lemli-Opitz syndrome and X-linked dominant chondrodysplasia punctata) in which the hepatic cholesterol levels were far greater. In this study, we demonstrate abnormal accumulation of sterol precursors of cholesterol in membrane lipid rafts (detergent resistance membranes) prepared from liver tissues of these 2 infants: 8-dehydrocholesterol and 7-dehydrocholesterol in lipid rafts of the infant with Smith-Lemli-Opitz syndrome and cholest-8(9)-ene-3beta-ol in lipid rafts of the infant with X-linked dominant chondrodysplasia punctata. We suggest that such alterations in the lipid raft sterol environment may affect the biology of cells and the development of fetuses with cholesterol biosynthetic disorders.
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Affiliation(s)
- Dinesh Rakheja
- Department of Pathology, Children's Medical Center, Dallas, TX, USA.
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31
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Waye JS, Eng B, Potter MA, Nowaczyk MJM, McFadden D, Langlois S. De novo mutation of the DHCR7 gene in a fetus with severe Smith-Lemli-Opitz (or RSH) syndrome. Am J Med Genet A 2008; 143A:1799-801. [PMID: 17595012 DOI: 10.1002/ajmg.a.31802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- John S Waye
- 1Hamilton Regional Laboratory Medicine Program, Hamilton, Ontario, Canada.
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32
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Rossi M, D'Armiento M, Parisi I, Ferrari P, Hall CM, Cervasio M, Rivasi F, Balli F, Vecchione R, Corso G, Andria G, Parenti G. Clinical phenotype of lathosterolosis. Am J Med Genet A 2007; 143A:2371-81. [PMID: 17853487 DOI: 10.1002/ajmg.a.31929] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [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: 12/28/2022]
Abstract
Lathosterolosis (LS) is a defect of cholesterol biosynthesis due to the deficiency of the enzyme sterol-C5-desaturase. Only two patients have been described to date, both presenting with multiple malformations, mental retardation, and liver involvement. In addition in one of them pathological examination revealed mucolipidosis-like inclusions on optic microscopy analysis, and peculiar lysosomal lamellar bodies on electron microscopy analysis. This study is focused on a better characterization of the clinical phenotype of LS. We describe a further case in a fetus, sibling of the first patient reported, presenting with neural tube defect, craniofacial and limb anomalies, and prenatal liver involvement. The fetal phenotype suggests the possible occurrence of significant intrafamilial variability in LS, and expands the phenotypic spectrum of the disease. Histological examination of autopsy samples from the fetus and skin fibroblasts from the living sibling suggested that the mucolipidosis-like picture previously reported is not a constant feature of LS, being possibly associated with the most severe biochemical defects, but confirmed the ultrastructural finding of lamellar inclusions. The LS phenotype appears to be characterized by the distinctive association of a recognizable pattern of congenital anomalies, involving axial and appendicular skeleton, liver, central nervous and urogenital systems, and lysosomal storage. This condition partially overlaps with other defects of sterol metabolism, suggesting intriguing pathogenic links among these conditions.
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Affiliation(s)
- Massimiliano Rossi
- Dipartimento di Pediatria, Federico II University, Naples, Italy, and Department of Radiology, Great Ormond Street Hospital for Children, London, UK
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33
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Winter J, Kunath M, Roepcke S, Krause S, Schneider R, Schweiger S. Alternative polyadenylation signals and promoters act in concert to control tissue-specific expression of the Opitz Syndrome gene MID1. BMC Mol Biol 2007; 8:105. [PMID: 18005432 PMCID: PMC2248598 DOI: 10.1186/1471-2199-8-105] [Citation(s) in RCA: 21] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Accepted: 11/15/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mutations in the X-linked MID1 gene are responsible for Opitz G/BBB syndrome, a malformation disorder of developing midline structures. Previous Northern blot analyses revealed the existence of at least three MID1 transcripts of differing lengths. RESULTS Here we show that alternative polyadenylation generates the size differences observed in the Northern blot analyses. Analysis of EST data together with additional Northern blot analyses proved tissue-specific usage of the alternative polyadenylation sites. Bioinformatic characterization of the different 3'UTRs of MID1 revealed numerous RNA-protein interaction motifs, several of which turned out to be conserved between different species. Furthermore, our data suggest that mRNA termination at different polyadenylation sites is predetermined by the choice of alternative 5'UTRs and promoters of the MID1 gene, a mechanism that efficiently allows synergistic function of 5' and 3'UTRs. CONCLUSION MID1 expression is tightly regulated through concerted action of alternative promoters and alternative polyadenylation signals both during embryonic development and in the adult.
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Affiliation(s)
- Jennifer Winter
- Max-Planck Institute for Molecular Genetics, Berlin-Dahlem, Germany
| | - Melanie Kunath
- Max-Planck Institute for Molecular Genetics, Berlin-Dahlem, Germany
| | - Stefan Roepcke
- Max-Planck Institute for Molecular Genetics, Berlin-Dahlem, Germany
- ALTANA Pharma AG, Preclinical Research Bioinformatics, Konstanz, Germany
| | - Sven Krause
- Max-Planck Institute for Molecular Genetics, Berlin-Dahlem, Germany
| | | | - Susann Schweiger
- Max-Planck Institute for Molecular Genetics, Berlin-Dahlem, Germany
- Department of Dermatology, Charité-Hospital, Berlin, Germany
- Department of Neuroscience and Pathology, College of Medicine, University of Dundee, Dundee, UK
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Blahakova I, Makaturova E, Kotrbova L, Soukupova M, Lastuvkova J, Kozak L. Molecular screening of Smith-Lemli-Opitz syndrome in pregnant women from the Czech Republic. J Inherit Metab Dis 2007; 30:964-9. [PMID: 17994283 DOI: 10.1007/s10545-007-0710-z] [Citation(s) in RCA: 1] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Revised: 09/18/2007] [Accepted: 09/19/2007] [Indexed: 10/22/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive metabolic disorder. SLOS is caused by the mutations in the gene for 3beta-hydroxysterol Delta(7) reductase (DHCR7; EC 1.3.1.21), which maps to chromosome 11q12-13. DHCR7 catalyses the final step in cholesterol biosynthesis-the reduction of 7-dehydrocholesterol to cholesterol. Clinical severity ranges from mild dysmorphism to severe congenital malformation and intrauterine lethality. Pregnant women are offered a biochemical screening test for Down syndrome in the second trimester, where the suspicion for SLOS could be registered, when the unconjugated estriol (uE3) level appears low. A group of 456 fetuses with a high risk for SLOS were examined by DNA analysis. We confirmed SLOS in 5 fetuses and 11 fetuses were carriers. One novel mutation (p.G30A) was detected. The most frequently found mutations, c.964-1G > C and p.W151X, are also the most severe ones. At least one of these mutations was detected in each fetus with SLOS. This suggests that the biochemical screening of pregnant women probably uncovers mainly more severely affected fetuses. We confirmed SLOS also in two patients whose prenatal screening was negative. Both of them had nonsense mutation on one allele. It stands to reason that some modifying factors may play a role in the reduction of the uE3 level in the mother's serum.
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Affiliation(s)
- I Blahakova
- Center of Molecular Biology and Gene Therapy, University Hospital Brno, Brno, Czech Republic.
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35
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Abstract
OBJECTIVES We review our experience using mutation analysis of the DHCR7 gene for prenatal diagnosis of Smith-Lemli-Opitz syndrome (SLOS), an autosomal recessive disorder of endogenous cholesterol biosynthesis caused by deficiency of 7-dehydrocholesterol reductase (DHCR7). METHODS AND RESULTS Prenatal diagnosis of SLOS was conducted for 21 pregnancies involving 15 families. DNA was isolated directly from amniotic fluid cells or chorionic villus samples (CVS), and the DHCR7 gene was screened for the parental mutations using PCR-ARMS and nucleotide sequencing. Sixteen of the pregnancies were unaffected and five were affected. There have been no incidences of misdiagnosed pregnancies. CONCLUSIONS DHCR7 mutation is a rapid and reliable method for prenatal diagnosis of SLOS, and provides an alternative to specialized biochemical tests for elevated 7DHC in amniotic fluid or CVS.
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Affiliation(s)
- John S Waye
- Hamilton Regional Laboratory Medicine Program, Hamilton Health Sciences, Hamilton ON, Canada L8N 3Z5, Canada.
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Plösch T, van Straten EME, Kuipers F. Cholesterol Transport by the Placenta: Placental Liver X Receptor Activity as a Modulator of Fetal Cholesterol Metabolism? Placenta 2007; 28:604-10. [PMID: 17141866 DOI: 10.1016/j.placenta.2006.10.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [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: 07/21/2006] [Revised: 10/17/2006] [Accepted: 10/18/2006] [Indexed: 11/30/2022]
Abstract
Cholesterol is an important sterol in mammals. Defects in cholesterol synthesis or intracellular routing have devastating consequences already in utero: the Smith-Lemli-Opitz syndrome, desmosterolosis and Niemann-Pick C1 disease provide examples of severe human inherited diseases caused by mutations in cholesterol metabolism genes. On the other hand, elevated plasma cholesterol concentrations are associated with the development of atherosclerosis which represents a major health risk in Western societies. Moreover, several studies indicate that development of atherosclerosis may already start during fetal life. Hence, a carefully balanced regulation of cholesterol metabolism appears of critical importance for both the development of the fetus and health of the adult. In the adult, the liver X receptor is a key regulator of cholesterol metabolism. Its target genes regulate cellular cholesterol efflux and thereby modulate whole-body cholesterol fluxes. LXR and several of its target genes have recently been demonstrated to be expressed in the placenta, which would provide a means to control delivery of maternal cholesterol to the fetus. Here we discuss the potential role of the placenta in the regulation of fetal cholesterol homeostasis and strategies to influence maternal-fetal cholesterol transfer.
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Affiliation(s)
- T Plösch
- Center for Liver, Digestive and Metabolic Diseases, Laboratory of Pediatrics, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
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Haas D, Garbade SF, Vohwinkel C, Muschol N, Trefz FK, Penzien JM, Zschocke J, Hoffmann GF, Burgard P. Effects of cholesterol and simvastatin treatment in patients with Smith-Lemli-Opitz syndrome (SLOS). J Inherit Metab Dis 2007; 30:375-87. [PMID: 17497248 DOI: 10.1007/s10545-007-0537-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [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: 12/13/2006] [Revised: 03/28/2007] [Accepted: 03/29/2007] [Indexed: 01/20/2023]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a malformation syndrome caused by deficiency of 7-dehydrocholesterol reductase catalysing the last step of cholesterol biosynthesis. This results in an accumulation of 7- and 8-dehydrocholesterol (7 + 8-DHC) and, in most patients, a deficiency of cholesterol. Current therapy consists of dietary cholesterol supplementation, which raises plasma cholesterol levels, but clinical effects have been reported in only a few patients. Hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors were shown to reduce 7 + 8-DHC levels and increase cholesterol concentrations in two small trials with divergent clinical outcome. This retrolective study evaluates the effects of cholesterol only and of cholesterol plus the HMG-CoA reductase inhibitor simvastatin on plasma sterols in 39 SLOS patients and on anthropometric measures in 20 SLOS patients. Cholesterol as well as additional simvastatin decreased the plasma (7 + 8-DHC)/cholesterol ratio. However, the mechanism leading to the decreasing ratio was different. Whereas it was due to an increasing cholesterol concentration in the cholesterol-only cohort, a decreasing 7 + 8-DHC concentration was demonstrated in the cohort receiving additional simvastatin. We could not confirm a positive effect of simvastatin treatment on anthropometric measures or behaviour, as previously reported.
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Affiliation(s)
- D Haas
- Department of General Pediatrics, Division of Inborn Metabolic Diseases, University Hospital for Pediatric and Adolescent Medicine, Im Neuenheimer Feld 153, D-69120, Heidelberg, Germany.
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Solcà C, Pandit B, Yu H, Tint GS, Patel SB. Loss of apolipoprotein E exacerbates the neonatal lethality of the Smith-Lemli-Opitz syndrome mouse. Mol Genet Metab 2007; 91:7-14. [PMID: 17197219 PMCID: PMC1852500 DOI: 10.1016/j.ymgme.2006.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [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: 11/17/2006] [Accepted: 11/17/2006] [Indexed: 11/19/2022]
Abstract
The Smith-Lemli-Opitz syndrome (SLOS) is caused by a genetic defect in cholesterol biosynthesis; mutations in the enzyme 3ss-hydroxysterol Delta7 reductase (Dhcr7) lead to a failure of cholesterol (and desmosterol) synthesis, with an accumulation of precursor sterols, such as 7-dehydrocholesterol. Extensive genotype-phenotype analyses have indicated that there is considerable variation in the severity of the disease, much of which is not explained by defects in the Dhcr7 gene alone. Factors ranging from variations in maternal-fetal cholesterol transfer during pregnancy, to other genetic factors have been proposed to account for this variability. Variations at the APOE locus affect plasma cholesterol levels in humans and this polymorphic gene has been found to be associated with cardiovascular as well as neurological disorders. This locus has recently been implicated in accounting for some of the variations in SLOS. To address whether maternal hypercholesterolemia can affect fetal outcome, we tested the ability of maternal hypercholesterolemia to rescue the neonatal lethality in a mouse model of SLOS. Maternal hypercholesterolemia, induced by ApoE or Ldl-r deficiency not only failed to ameliorate the postnatal lethality, it increased the prenatal mortality of Dhcr7 deficient pups. Thus the murine data suggest that maternal loss of ApoE or Ldl-r function further exacerbates the neonatal lethality, suggesting they may play a role in maternal transfer of cholesterol to the embryo.
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Affiliation(s)
- Curzio Solcà
- Division of Endocrinology, Metabolism and Clinical Nutrition, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Yu H, Li M, Tint GS, Chen J, Xu G, Patel SB. Selective reconstitution of liver cholesterol biosynthesis promotes lung maturation but does not prevent neonatal lethality in Dhcr7 null mice. BMC Dev Biol 2007; 7:27. [PMID: 17408495 PMCID: PMC1855921 DOI: 10.1186/1471-213x-7-27] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 04/04/2007] [Indexed: 11/10/2022]
Abstract
Background Targeted disruption of the murine 3β-hydroxysterol-Δ7-reductase gene (Dhcr7), an animal model of Smith-Lemli-Opitz syndrome, leads to loss of cholesterol synthesis and neonatal death that can be partially rescued by transgenic replacement of DHCR7 expression in brain during embryogenesis. To gain further insight into the role of non-brain tissue cholesterol deficiency in the pathophysiology, we tested whether the lethal phenotype could be abrogated by selective transgenic complementation with DHCR7 expression in the liver. Results We generated mice that carried a liver-specific human DHCR7 transgene whose expression was driven by the human apolipoprotein E (ApoE) promoter and its associated liver-specific enhancer. These mice were then crossed with Dhcr7+/- mutants to generate Dhcr7-/- mice bearing a human DHCR7 transgene. Robust hepatic transgene expression resulted in significant improvement of cholesterol homeostasis with cholesterol concentrations increasing to 80~90 % of normal levels in liver and lung. Significantly, cholesterol deficiency in brain was not altered. Although late gestational lung sacculation defect reported previously was significantly improved, there was no parallel increase in postnatal survival in the transgenic mutant mice. Conclusion The reconstitution of DHCR7 function selectively in liver induced a significant improvement of cholesterol homeostasis in non-brain tissues, but failed to rescue the neonatal lethality of Dhcr7 null mice. These results provided further evidence that CNS defects caused by Dhcr7 null likely play a major role in the lethal pathogenesis of Dhcr7-/- mice, with the peripheral organs contributing the morbidity.
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Affiliation(s)
- Hongwei Yu
- Division of Endocrinology, Metabolism and Nutrition, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Man Li
- Division of Endocrinology, Metabolism and Nutrition, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Qilu Hospital of Shandong University, 44 West Wenhua Road Jinan, 250012, P. R. China
| | - G Stephen Tint
- Research Service, Department of Veterans Affairs New Jersey Health Care System, East Orange, NJ 07018, USA
- Department of Medicine, UMDNJ-New Jersey Medical School, Newark, NJ 07103-2714, USA
| | - Jianliang Chen
- Division of Endocrinology, Metabolism and Nutrition, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Guorong Xu
- Research Service, Department of Veterans Affairs New Jersey Health Care System, East Orange, NJ 07018, USA
- Department of Medicine, UMDNJ-New Jersey Medical School, Newark, NJ 07103-2714, USA
| | - Shailendra B Patel
- Division of Endocrinology, Metabolism and Nutrition, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Department of Veterans Affairs, Clement J. Zablocki Medical Center, Milwaukee, WI 53295, USA
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40
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Bzduch V, Behulova D, Kozak L. Sacral dimple as a skin manifestation of the Smith-Lemli-Opitz syndrome. J Inherit Metab Dis 2007; 30:269-70. [PMID: 17347909 DOI: 10.1007/s10545-007-0564-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2007] [Revised: 01/21/2007] [Accepted: 01/25/2007] [Indexed: 10/23/2022]
Affiliation(s)
- V Bzduch
- First Department of Pediatrics, Comenius University Children's Hospital, Bratislava, Slovakia.
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41
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Walencka Z, Baumert M, Paprotny M, Jezela-Stanek A, Małunowicz EM, Sikora J. [The Smith-Lemli-Opitz syndrome--case report, early diagnosis]. Ginekol Pol 2007; 78:242-4. [PMID: 17650909] [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: 05/16/2023] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is one of the most frequent metabolic disorders in Poland and manifests itself with multiple congenital anomalies, psychomotor delay and intellectual disability. It is caused by mutations in DHCR7 gene, which codes one of the cholesterol biosynthesis enzymes. Clinical diagnosis of the syndrome is difficult due to lack of pathognomonic features and their variable expression. Despite high carrier frequency in Poland, SLO syndrome is rarely suspected and recognized. Its early diagnosis is essential, mainly because of high genetic risk (25%) as well as possibilities of treatment. Authors present a female-newborn, diagnosed with SLOS during the neonatal period. The diagnosis was based on biochemical and molecular tests. Mutations in DHCR7 gene have been found in both, the child and the parents.
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Affiliation(s)
- Zofia Walencka
- Klinika Neonatologii Katedry Połoznictwa i Ginekologii S.A.M. w Katowicach.
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Abstract
We describe the autopsy of a chromosomally normal multiple-anomaly fetus with left side-restricted malformations, terminated after routine screening ultrasound. Autopsy findings were remarkable for severe left-sided craniofacial malformations including a cleft left frontal calavarial bone and an oblique facial cleft. Internal examination showed multiple left-sided malformations including severe left ventricular hypoplasia and interrupted aortic arch. A hypoplastic left lung, an accessory spleen, and an absent left kidney and left ureter were also discovered. Some features of the Smith-Lemli-Opitz Syndrome (SLOS) are found in this fetus, yet the occurrence of left side-restricted anomalies indicates that developmental mechanisms responsible for body laterality are involved. Potential mechanisms leading to this constellation of anomalies include a ciliary defect, side-restricted chromosomal mosaicism, or a teratogenic insult, affecting developmental morphogens, including sonic hedgehog. The sonic hedgehog pathway is important in the molecular mechanisms underlying SLOS and in laterality development in the early embryo.
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Affiliation(s)
- Meghan Delaney
- Beth Israel Deaconess Medical Center, Department of Pathology, 330 Brookline Avenue, Boston, MA 02215, USA.
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43
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Ciara E, Popowska E, Piekutowska-Abramczuk D, Jurkiewicz D, Borucka-Mankiewicz M, Kowalski P, Goryluk-Kozakiewicz B, Nowaczyk MJM, Krajewska-Walasek M. SLOS carrier frequency in Poland as determined by screening for Trp151X and Val326Leu DHCR7 mutations. Eur J Med Genet 2006; 49:499-504. [PMID: 16497572 DOI: 10.1016/j.ejmg.2006.01.006] [Citation(s) in RCA: 19] [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] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Accepted: 01/17/2006] [Indexed: 11/19/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol biosynthesis caused by mutations in the DHCR7 gene. Previous studies estimated the prevalence of SLOS between 1 in 10,000 to 1 in 70,358 based on case frequency surveys. Although panethnic, SLOS appears to be most frequent in Central European populations (Czech Republic 1 in 10,000, Slovakia 1 in 15,000 - 1 in 20,000). In Polish individuals with SLOS two DHCR7 mutations, c.452G>A (p.Trp151X) and c.976G>T (p.Val326Leu), account for 65.2% of all observed DHCR7 mutations. We analyzed 2169 samples for the p.Trp151X mutation and 2087 for the p.Val326Leu mutation. The combined carrier frequency of these two mutations of was 2.40+/-0.32%, yielding a calculated incidence of SLOS in Poland of 2.5 4x10(-4)-4.3 5x10(-4) (1 in 2,300 to 1 in 3,937) placing SLOS among the most common recessive genetic disorders in Poland.
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Affiliation(s)
- E Ciara
- Department of Medical Genetics, Children's Memorial Health Institute, Al. Dzieci Polskich 20, 04-730 Warsaw, Poland.
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44
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Matsumoto H, Matsuura S, Tsukahara M. [Smith-Lemli-Opitz syndrome]. Nihon Rinsho 2006; Suppl 3:488-91. [PMID: 17022594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Affiliation(s)
- Hiroshi Matsumoto
- Department of Radiation Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University
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45
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Sikora DM, Pettit-Kekel K, Penfield J, Merkens LS, Steiner RD. The near universal presence of autism spectrum disorders in children with Smith-Lemli-Opitz syndrome. Am J Med Genet A 2006; 140:1511-8. [PMID: 16761297 DOI: 10.1002/ajmg.a.31294] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [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: 11/09/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive condition caused by a defect in cholesterol synthesis. Affected children often have malformations and mental retardation. Autistic behaviors also are evident. The purpose of the present study was to determine the prevalence of autism spectrum disorders (ASDs) in children with SLOS. Fourteen children, 3-16 years old, were evaluated using three different methods to document autistic symptoms: (a) parent interview, (b) direct observation, and (c) a behavior checklist. Blood sterols were also measured at regular intervals. Each subject was determined to have Autistic Disorder, Pervasive Developmental Disorder, not otherwise specified (PDD NOS), or no diagnosis on the autism spectrum, based on DSM-IV criteria. Correlations among variables were calculated, and blood sterol levels were compared between diagnostic groups. Approximately three-fourths of the children with SLOS (71-86% depending on the evaluation method) had an ASD, about 50% diagnosed with Autistic Disorder and the rest with PDD NOS. The children's baseline cholesterol, 7-dehydrocholesterol (7-DHC), and 8-dehydrocholesterol (8-DHC) levels, and cholesterol levels following supplementation did not correlate with the presence or severity of autistic symptoms. These results suggest that most children with SLOS have some variant of autism. SLOS appears to have the most consistent relationship with autism of any single gene disorder. Therefore, a link between cholesterol metabolism and autism is suggested. With further study, these findings, together with knowledge of the genetic and biochemical defects in SLOS, will likely provide valuable insights into the causes of autism in general.
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Affiliation(s)
- Darryn M Sikora
- Department of Pediatrics and Molecular, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, 97207, USA.
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46
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Correa-Cerro LS, Wassif CA, Waye JS, Krakowiak PA, Cozma D, Dobson NR, Levin SW, Anadiotis G, Steiner RD, Krajewska-Walasek M, Nowaczyk MJM, Porter FD. DHCR7 nonsense mutations and characterisation of mRNA nonsense mediated decay in Smith-Lemli-Opitz syndrome. J Med Genet 2006; 42:350-7. [PMID: 15805162 PMCID: PMC1736027 DOI: 10.1136/jmg.2004.022749] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
The Smith-Lemli-Opitz syndrome has only recently been added to the small number of congenital disorders characterized by photosensitivity. The clinical features of this disorder are distinct from other photosensitivity syndromes. Details on the patho-mechanism of photosensitivity in the Smith-Lemli-Opitz syndrome have yet to be fully determined. However, preliminary evidence points to the deranged cholesterol metabolism that characterizes the syndrome as causal in this UVA-mediated photosensitivity disorder.
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Affiliation(s)
- Alex Anstey
- Academic Department of Dermatology, College of Medicine, Cardiff University, Cardiff, UK.
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48
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Witsch-Baumgartner M, Clayton P, Clusellas N, Haas D, Kelley RI, Krajewska-Walasek M, Lechner S, Rossi M, Zschocke J, Utermann G. Identification of 14 novel mutations in DHCR7 causing the Smith-Lemli-Opitz syndrome and delineation of the DHCR7 mutational spectra in Spain and Italy. Hum Mutat 2006; 25:412. [PMID: 15776424 DOI: 10.1002/humu.9328] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The Smith-Lemli-Opitz syndrome (SLOS) is a phenotypically variable metabolic malformation and mental retardation syndrome for which more than 80 mutations in the DHCR7 disease-causing gene have been described. The DHCR7 mutational spectra differ significantly in different areas of Europe, and several common putative founder mutations account for a substantial fraction of all mutations in some ethnic groups. Here we have analysed 47 SLOS patients and describe 14 newly identified mutations in 18 SLOS patients of Ashkenazi Jewish, Austrian, British, German, Italian, Irish, Polish, Portuguese, and Spanish origins. Half of the new mutations are in the transmembrane domains of the protein. In addition, there were two null mutations, one mutation in the 4th cytoplasmic loop, two mutations in the first and last codons, and three mutations in other regions such as the second cytoplasmic loop and the first endoplasmic loop. The analysis included 20 Spanish and 12 Italian SLOS patients and revealed very different mutation spectra in these patients compared to previously described patients from Czechoslovakia, Germany, Poland, and the UK and implicated p.Thr93Met on the J haplotype as the most frequent Mediterranean founder mutation.
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Affiliation(s)
- M Witsch-Baumgartner
- Department of Medical Biology and Human Genetics, Medical University Innsbruck, Innsbruck, Austria.
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49
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Abstract
Cholesterol regulates Hedgehog (Hh) signaling during early vertebrate development. Smith-Lemli-Opitz syndrome (SLOS) is caused by defects in 7-dehydrocholesterol reductase (DHCR7), an enzyme catalyzing the final step of cholesterol biosynthesis. Many developmental malformations attributed to SLOS occur in tissues and organs where Hh signaling is required for development, but the precise role of DHCR7 deficiency in this disease remains murky. We report that DHCR7 and Sonic Hedgehog (Shh) are co-expressed during midline development in Xenopus embryos. DHCR7 has previously been implicated to function as a positive regulator of Hh signaling that acts to regulate the cholesterol adduction of Hh ligand or to affect Hh signaling in the responding cell. We present gain- and loss-of-function analyses suggesting that DHCR7 functions as a negative regulator of Hh signaling at the level or downstream of Smoothened (Smo) and affects intracellular Hh signaling. Our analysis also raises the possibility that the human condition SLOS is caused not only by disruption of the enzymatic role of DHCR7 as a reductase in cholesterol biosynthesis, but may also involve defects in DHCR7 resulting in derepression of Shh signaling.
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Affiliation(s)
- Tetsuya Koide
- Department of Developmental and Cell Biology, and Developmental Biology Center, University of California, Irvine, CA 92697-2300, USA
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50
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Romano F, Fiore B, Pezzino FM, Longombardo MT, Cefalù AB, Noto D, Puglisi A, Brogna A, Mattina T, Averna M, Travali S. A novel mutation of the DHCR7 gene in a sicilian compound heterozygote with Smith-Lemli-Opitz Syndrome. ACTA ACUST UNITED AC 2006; 9:201-4. [PMID: 16392899 DOI: 10.1007/bf03260092] [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: 10/27/2022]
Abstract
INTRODUCTION Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol biosynthesis, resulting from deficient 7-dehydrocholesterol reductase (3beta-hydroxysterol Delta7-reductase) activity, the enzyme responsible for conversion of 7-dehydrocholesterol to cholesterol. SLOS is most common among people of European descent, with a reported incidence of 1 per 20,000-60,000 newborns, depending on the diagnostic criteria and the reference population. More than 80 different mutations have been identified in several hundred patients. In Italy, SLOS appears to be a rare condition, probably because of underdiagnosis. METHOD We analyzed by direct sequencing the 7-dehydrocholesterol reductase gene (DHCR7) in a Sicilian patient with Smith-Lemli-Opitz syndrome and his parents in order to characterize the molecular defect. RESULTS The molecular analysis of the coding exons and the intron-exon boundaries of the DHCR7 gene demonstrated the presence of two missense mutations: a novel mutation (I251N) and a known mutation (E288K) responsible in a compound heterozygous state for a severe form of SLOS. CONCLUSION The present study describes a Sicilian patient, a carrier of a novel mutation of the DHCR7 gene (I251N), which is responsible in a compound heterozygous state for a severe form of SLOS.
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Affiliation(s)
- Fabrizio Romano
- Department of Biomedical Sciences, Section of Clinical Pathology and Molecular Oncology, University of Catania, Catania, Italy
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