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Chorin O, Hirsch Y, Rock R, Salzer Sheelo L, Goldberg Y, Mandel H, Hershkovitz T, Fleischer N, Greenbaum L, Katz U, Barel O, Hamed N, Ben-Zeev B, Greenberger S, Nasser Samra N, Stern Zimmer M, Raas-Rothschild A, Pode-Shakked B. Vici syndrome in Israel: Clinical and molecular insights. Front Genet 2022; 13:991721. [PMID: 36204321 PMCID: PMC9531146 DOI: 10.3389/fgene.2022.991721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
Introduction: Vici Syndrome is a rare, severe, neurodevelopmental/neurodegenerative disorder with multi-systemic manifestations presenting in infancy. It is mainly characterized by global developmental delay, seizures, agenesis of the corpus callosum, hair and skin hypopigmentation, bilateral cataract, and varying degrees of immunodeficiency, among other features. Vici Syndrome is caused by biallelic pathogenic variants in EPG5, resulting in impaired autophagy. Thus far, the condition has been reported in less than a hundred individuals. Objective and Methods: We aimed to characterize the clinical and molecular findings in individuals harboring biallelic EPG5 variants, recruited from four medical centers in Israel. Furthermore, we aimed to utilize a machine learning-based tool to assess facial features of Vici syndrome. Results: Eleven cases of Vici Syndrome from five unrelated families, one of which was diagnosed prenatally with subsequent termination of pregnancy, were recruited. A total of five disease causing variants were detected in EPG5: two novel: c.2554-5A>G and c.1461delC; and 3 previously reported: c.3447G>A, c.5993C>G, and c.1007A>G, the latter previously identified in several patients of Ashkenazi-Jewish (AJ) descent. Amongst 140,491 individuals screened by the Dor Yeshorim Program, we show that the c.1007A>G variant has an overall carrier frequency of 0.45% (1 in 224) among AJ individuals. Finally, based on two-dimensional facial photographs of individuals with Vici syndrome (n = 19), a composite facial mask was created using the DeepGestalt algorithm, illustrating facial features typical of this disorder. Conclusion: We report on ten children and one fetus from five unrelated families, affected with Vici syndrome, and describe prenatal and postnatal characteristics. Our findings contribute to the current knowledge regarding the molecular basis and phenotypic features of this rare syndrome. Additionally, the deep learning-based facial gestalt adds to the clinician’s diagnostic toolbox and may aid in facilitating identification of affected individuals.
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Affiliation(s)
- Odelia Chorin
- The Institute for Rare Diseases, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- *Correspondence: Odelia Chorin,
| | - Yoel Hirsch
- Dor Yeshorim, Committee for Prevention of Jewish Genetic Diseases, New York, NY, United States
| | - Rachel Rock
- The Institute for Rare Diseases, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
| | - Liat Salzer Sheelo
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- Raphael Recanati Genetic Institute, Rabin Medical Center—Beilinson Hospital, Petah Tikva, Israel
| | - Yael Goldberg
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- Raphael Recanati Genetic Institute, Rabin Medical Center—Beilinson Hospital, Petah Tikva, Israel
| | - Hanna Mandel
- Unit of Inherited Metabolic Disorders, Ziv Medical Center, Safed, Israel
- Institute of Human Genetics, Ziv Medical Center, Safed, Israel
| | - Tova Hershkovitz
- The Genetics Institute, Rambam Health Care Campus, Haifa, Israel
- Ruth and Bruce Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel
| | | | - Lior Greenbaum
- The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- The Joseph Sagol Neusroscience Center, Sheba Medical Center, Ramat Gan, Israel
| | - Uriel Katz
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- Pediatric Heart Institute, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
| | - Ortal Barel
- The Genomic Unit, Sheba Cancer Research Center, Sheba Medical Center, Ramat Gan, Israel
- The Wohl Institute for Translational Medicine and Cancer Research Center, Sheba Medical Center, Ramat Gan, Israel
| | - Nasrin Hamed
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- Pediatric Neurology Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
| | - Bruria Ben-Zeev
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- Pediatric Neurology Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
| | - Shoshana Greenberger
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- The Talpiot Medical Leadership Program, Sheba Medical Center, Ramat Gan, Israel
- Department of Dermatology, Sheba Medical Center, Ramat Gan, Israel
| | - Nadra Nasser Samra
- Institute of Human Genetics, Ziv Medical Center, Safed, Israel
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Michal Stern Zimmer
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- Pediatric Neurology Unit, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
- Pediatric Department B, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
| | - Annick Raas-Rothschild
- The Institute for Rare Diseases, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
| | - Ben Pode-Shakked
- The Institute for Rare Diseases, Edmond and Lily Safra Children’s Hospital, Sheba Medical Center, Ramat Gan, Israel
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
- The Talpiot Medical Leadership Program, Sheba Medical Center, Ramat Gan, Israel
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Chrzanowska-Steglińska M, Moczulska H, Skoczylas B, Pietrusiński M, Antosik K, Jakiel P, Kacprzak M, Borowiec M, Sieroszewski P. Occurrence of c.976 G>T (p.Val326Leu) and c.452 G>A (p.Trp151Ter) variants in DHCR7 gene in population of polish women with recurrent miscarriage. Eur J Obstet Gynecol Reprod Biol 2020; 252:252-255. [PMID: 32629226 DOI: 10.1016/j.ejogrb.2020.05.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Recurrent miscarriage is a serious clinical problem that affects 1-5 % of all couples trying to conceive. Although the incidence of Smith-Lemli-Opitz Syndrome (SLOS, OMIM #270400), an autosomal recessive condition caused by variants in the DHCR7 gene, is very low, (1:83 000), the observed carrier frequency of DHCR7 gene variants in the Polish population is high, ranging from 1:24 to 1:31. It is possible that this carriage may be responsible for early pregnancy loss. OBJECTIVES The aim of the study is to determine the carrier frequency of the p c.976 G>T (p.Val326Leu) and c.452 G>A (p.Trp151Ter) variants in the DHCR7 gene in patients experiencing recurrent miscarriage. METHODS The study group included 480 patients: a study group of 380 with at least 2 miscarriages before the 20th week of pregnancy, and a control group of 100 who had not experienced miscarriage. The variants were identified by genotyping: c.976 G>T (p.Val326Leu) by the TaqMan® SNP Genotyping Assay system, and c.452 G>A (p.Trp151Ter) using the BfaI restriction enzyme. Statistical analysis was performed using R software. RESULTS No examples of c.976 G>T (p.Val326Leu) were found in either group. c.452 G>A (p.Trp151Ter) was found in 22 participants from the study group and 4 from the control group; however, this difference was not significant (Chi2 test p = 0.61). CONCLUSIONS Being a carrier of the c.976 G>T (p.Val326Leu) and c.452 G>A (p.Trp151Ter) variants in theDHCR7 gene is not a risk factor for recurrent miscarriage in the Polish population.
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Affiliation(s)
| | - Hanna Moczulska
- Department of Clinical and Laboratory Genetics, the Medical University of Lodz, Poland; Clinical Genetics Clinic, Central Clinical Hospital of the Medical University of Lodz, Poland
| | - Beata Skoczylas
- Department of Clinical and Laboratory Genetics, the Medical University of Lodz, Poland
| | - Michał Pietrusiński
- Department of Clinical and Laboratory Genetics, the Medical University of Lodz, Poland
| | - Karolina Antosik
- Department of Clinical and Laboratory Genetics, the Medical University of Lodz, Poland
| | - Paulina Jakiel
- Department of Clinical and Laboratory Genetics, the Medical University of Lodz, Poland
| | - Marta Kacprzak
- Department of Fetal Medicine and Gynaecology, the Medical University of Lodz, Poland
| | - Maciej Borowiec
- Department of Clinical and Laboratory Genetics, the Medical University of Lodz, Poland
| | - Piotr Sieroszewski
- Department of Fetal Medicine and Gynaecology, the Medical University of Lodz, Poland
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Schoner K, Witsch-Baumgartner M, Behunova J, Petrovic R, Bald R, Kircher SG, Ramaswamy A, Kluge B, Meyer-Wittkopf M, Schmitz R, Fritz B, Zschocke J, Laccone F, Rehder H. Smith-Lemli-Opitz syndrome - Fetal phenotypes with special reference to the syndrome-specific internal malformation pattern. Birth Defects Res 2019; 112:175-185. [PMID: 31840946 PMCID: PMC7432161 DOI: 10.1002/bdr2.1620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/04/2019] [Accepted: 11/05/2019] [Indexed: 01/31/2023]
Abstract
Background Autosomal‐recessive SLOS is caused by mutations in the DHCR7 gene. It is defined as a highly variable complex of microcephaly with intellectual disability, characteristic facies, hypospadias, and polysyndactyly. Syndrome diagnosis is often missed at prenatal ultrasound and fetal autopsy Methods We performed autopsies and DHCR7 gene analyses in eight fetuses suspected of having SLOS and measured cholesterol values in long‐term formalin‐fixed tissues of an additional museum exhibit Results Five of the nine fetuses presented classical features of SLOS, including four cases with atrial/atrioventricular septal defects and renal anomalies, and one with additional bilateral renal agenesis and a Dandy‐Walker cyst. These cases allowed for diagnosis at autopsy and subsequent SLOS diagnosis in two siblings. Two fetuses were mildly affected and two fetuses showed additional holoprosencephaly. These four cases and the exhibit had escaped diagnosis at autopsy. The case with bilateral renal agenesis presented a novel combination of a null allele and a putative C‐terminus missense mutation in the DHCR7 gene Conclusions In view of the discrepancy between the prevalence of SLOS among newborns and the carrier frequency of a heterozygous DHCR7 gene mutation, the syndrome‐specific internal malformation pattern may be helpful not to miss SLOS diagnosis in fetuses at prenatal ultrasound and fetal autopsy
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Affiliation(s)
- Katharina Schoner
- Institute of Pathology, Philipps-University Marburg, Marburg, Germany
| | | | - Jana Behunova
- Institute of Medical Genetics, Medical University Vienna, Vienna, Austria
| | - Robert Petrovic
- Institute of Medical Biology, Comenius University Bratislava, Bratislava, Slovakia
| | - Rainer Bald
- Clinic of Gynecology and Obstetrics, Klinikum Leverkusen, Leverkusen, Germany
| | - Susanne G Kircher
- Institute of Medical Genetics, Medical University Vienna, Vienna, Austria
| | - Annette Ramaswamy
- Institute of Pathology, Philipps-University Marburg, Marburg, Germany
| | - Britta Kluge
- Institute of Medical Genetics, Medical University Vienna, Vienna, Austria
| | | | - Ralf Schmitz
- Clinic of Gynecology and Obstetrics, University Clinic Muenster, Münster, Germany
| | - Barbara Fritz
- Institute of Human Genetics, Philipps-University Marburg, Marburg, Germany
| | - Johannes Zschocke
- Institute of Human Genetics, Medical University Innsbruck, Innsbruck, Austria
| | - Franco Laccone
- Institute of Medical Genetics, Medical University Vienna, Vienna, Austria
| | - Helga Rehder
- Institute of Pathology, Philipps-University Marburg, Marburg, Germany.,Institute of Medical Genetics, Medical University Vienna, Vienna, Austria
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Glinton KE, Elsea SH. Untargeted Metabolomics for Autism Spectrum Disorders: Current Status and Future Directions. Front Psychiatry 2019; 10:647. [PMID: 31551836 PMCID: PMC6746843 DOI: 10.3389/fpsyt.2019.00647] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 08/12/2019] [Indexed: 12/20/2022] Open
Abstract
Autism spectrum disorders (ASDs) are a group of neurodevelopment disorders characterized by childhood onset deficits in social communication and interaction. Although the exact etiology of most cases of ASDs is unknown, a portion has been proposed to be associated with various metabolic abnormalities including mitochondrial dysfunction, disorders of cholesterol metabolism, and folate abnormalities. Targeted biochemical testing like plasma amino acid and acylcarnitine profiles have demonstrated limited utility in helping to diagnose and manage such patients. Untargeted metabolomics has emerged, however, as a promising tool in screening for underlying biochemical abnormalities and managing treatment and as a means of investigating possible novel biomarkers for the disorder. Here, we review the principles and methodology behind untargeted metabolomics, recent pilot studies utilizing this technology, and areas in which it may be integrated into the care of children with this disorder in the future.
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Affiliation(s)
- Kevin E. Glinton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Sarah H. Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
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Lazarin GA, Haque IS, Evans EA, Goldberg JD. Smith-Lemli-Opitz syndrome carrier frequency and estimates of in utero mortality rates. Prenat Diagn 2017; 37:350-355. [PMID: 28166604 PMCID: PMC5413855 DOI: 10.1002/pd.5018] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/23/2017] [Accepted: 01/25/2017] [Indexed: 12/19/2022]
Abstract
Objective To tabulate individual allele frequencies and total carrier frequency for Smith–Lemli–Opitz syndrome (SLOS) and compare expected versus observed birth incidences. Methods A total of 262 399 individuals with no known indication or increased probability of SLOS carrier status, primarily US based, were screened for SLOS mutations as part of an expanded carrier screening panel. Results were retrospectively analyzed to estimate carrier frequencies in multiple ethnic groups. SLOS birth incidences obtained from existing literature were then compared with these data to estimate the effect of SLOS on fetal survival. Results Smith–Lemli–Opitz syndrome carrier frequency is highest in Ashkenazi Jews (1 in 43) and Northern Europeans (1 in 54). Comparing predicted birth incidence with that observed in published literature suggests that approximately 42% to 88% of affected conceptuses experience prenatal demise. Conclusion Smith–Lemli–Opitz syndrome is relatively frequent in certain populations and, because of its impact on prenatal and postnatal morbidity and mortality, merits consideration for routine screening. © 2017 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd. What's already known about this topic?
Smith–Lemli–Opitz syndrome is an autosomal recessive multiple congenital anomaly syndrome with varying frequency estimates. Smith–Lemli–Opitz syndrome is presumed to be associated with an increased risk for pregnancy loss, although this risk has not been quantified.
What does this study add?
By reporting results from a large, diverse tested population, these data define the carrier frequency in multiple ethnic groups. Predicted Smith–Lemli–Opitz syndrome frequency at birth is compared with actual frequencies from previous studies, enabling estimation of the pregnancy loss frequency.
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Blassberg R, Macrae JI, Briscoe J, Jacob J. Reduced cholesterol levels impair Smoothened activation in Smith-Lemli-Opitz syndrome. Hum Mol Genet 2015; 25:693-705. [PMID: 26685159 PMCID: PMC4743690 DOI: 10.1093/hmg/ddv507] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 12/08/2015] [Indexed: 12/21/2022] Open
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a common autosomal-recessive disorder that results from mutations in the gene encoding the cholesterol biosynthetic enzyme 7-dehydrocholesterol reductase (DHCR7). Impaired DHCR7 function is associated with a spectrum of congenital malformations, intellectual impairment, epileptiform activity and autism spectrum disorder. Biochemically, there is a deficit in cholesterol and an accumulation of its metabolic precursor 7-dehydrocholesterol (7DHC) in developing tissues. Morphological abnormalities in SLOS resemble those seen in congenital Sonic Hedgehog (SHH)-deficient conditions, leading to the proposal that the pathogenesis of SLOS is mediated by aberrant SHH signalling. SHH signalling is transduced through the transmembrane protein Smoothened (SMO), which localizes to the primary cilium of a cell on activation and is both positively and negatively regulated by sterol molecules derived from cholesterol biosynthesis. One proposed mechanism of SLOS involves SMO dysregulation by altered sterol levels, but the salient sterol species has not been identified. Here, we clarify the relationship between disrupted cholesterol metabolism and reduced SHH signalling in SLOS by modelling the disorder in vitro. Our results indicate that a deficit in cholesterol, as opposed to an accumulation of 7DHC, impairs SMO activation and its localization to the primary cilium.
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Affiliation(s)
- Robert Blassberg
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London NW7 1AA, UK
| | - James I Macrae
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London NW7 1AA, UK
| | - James Briscoe
- The Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London NW7 1AA, UK
| | - John Jacob
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Level 6, West Wing, Oxford OX3 9DU, UK, Department of Neurology, Milton Keynes Hospital, Standing Way, Milton Keynes, Buckinghamshire MK6 5LD, UK and Department of Neurology, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK
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Oláh AV, Szabó GP, Varga J, Balogh L, Csábi G, Csákváry V, Erwa W, Balogh I. Relation between biomarkers and clinical severity in patients with Smith-Lemli-Opitz syndrome. Eur J Pediatr 2013; 172:623-30. [PMID: 23319240 DOI: 10.1007/s00431-012-1925-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Revised: 12/19/2012] [Accepted: 12/23/2012] [Indexed: 10/27/2022]
Abstract
UNLABELLED Smith-Lemli-Opitz syndrome (SLOS), a multiple congenital anomaly with severe mental retardation, is caused by decreased activity of 7-dehydrocholesterol reductase. Fifteen Hungarian patients were diagnosed with SLOS on the basis of clinical symptoms, serum cholesterol, 7-dehydrocholesterol, and molecular genetic testing. Their age at the time of diagnosis in mild SLOS (n = 4, clinical score <20) was 0.5-18 years, cholesterol was 2.37 ± 0.8 mmol/L, and 7DHC was 0.38 ± 0.14 mmol/L. In the group of typical SLOS (n = 7, score 20-50), the diagnosis was set up earlier (age of 0.1-7 years); t-cholesterol was 1.47 ± 0.7 mmol/L, and 7DHC was 0.53 ± 0.20 mmol/L. Patients with severe SLOS (n = 4, clinical score > 50) died as newborns and had the lowest t-cholesterol (0.66 ± 0.27 mmol/L), and 7DHC was 0.47 ± 0.14 mmol/L. Correlation coefficient with clinical severity was 0.74 for initial t-cholesterol and 0.669 for Cho/7DHC. Statistically significant difference was between the initial t-cholesterol of mild and severe SLOS (p = 0.01), and between the Cho/7DHC ratios of groups (p = 0.004). In severe SLOS, the percentage of α-lipoprotein was significantly lower than in typical (p = 0.003) and mild SLOS (p = 0.004). Although serum albumin, total bilirubin, and hemostasis parameters remained in the reference range during cholesterol supplementation (n = 10) combined with statin therapy (n = 9), increase of aspartate aminotransferase and alanine aminotransferase in 50 % of the patients probably refers to a reversible alteration of liver function; therefore, statin therapy was suspended. CONCLUSION life expectancy is fundamentally determined by the initial t-cholesterol, but dehydrocholesterol and α-lipoprotein have prognostic value. Accumulation of hepatotoxic DHC may inhibit the synthesis of α-lipoproteins, decreasing the reverse cholesterol transport. During statin therapy, we suggest monitoring of lipid parameters and liver function.
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Affiliation(s)
- Anna V Oláh
- Department of Laboratory Medicine, Medical and Health Science Center, University of Debrecen, 98 Nagyerdei krt., Debrecen 4032, Hungary.
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Nowaczyk MJM, Irons MB. Smith-Lemli-Opitz syndrome: phenotype, natural history, and epidemiology. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2012; 160C:250-62. [PMID: 23059950 DOI: 10.1002/ajmg.c.31343] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a congenital multiple anomaly/intellectual disability syndrome caused by a deficiency of cholesterol synthesis resulting from a deficiency of 7-dehydrocholesterol (7DHC) reductase encoded by DHCR7. SLOS is inherited in an autosomal recessive pattern. It is characterized by prenatal and postnatal growth retardation, microcephaly, a variable degree of intellectual disability that encompasses normal intelligence to severe intellectual deficiency, and multiple major and minor malformations. External malformations include distinctive facial features, cleft palate, postaxial polydactyly, 2-3 syndactyly of the toes, and underdeveloped external genitalia in males, while internal anomalies may affect every organ system. The clinical spectrum is wide, and rare individuals have been described with normal development and only minor malformations. The clinical diagnosis of SLOS is confirmed by demonstrating an abnormally elevated concentration of the cholesterol precursor, 7DHC, in serum or other tissues, or by the presence of two DHCR7 mutations. The enzymatic deficiency results in decreased cholesterol and increased 7DHC levels, both during embryonic development and after birth. The malformations found in SLOS may result from decreased cholesterol, increased 7DHC or a combination of these two factors. This review discusses the physical and behavioral phenotype of SLOS, the diagnostic approaches, the natural history from the prenatal period to adulthood, and current understanding of the pathophysiology of SLOS.
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Affiliation(s)
- Małgorzata J M Nowaczyk
- Department of Pathology and Molecular Medicine and Department of Pediatrics, McMaster University McMaster University Medical Centre, Room 3N16, 1200 Main Street West, Hamilton ON, Canada L8S 4J9.
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Nowaczyk MJ, Tan M, Hamid JS, Allanson JE. Smith-Lemli-Opitz syndrome: Objective assessment of facial phenotype. Am J Med Genet A 2012; 158A:1020-8. [DOI: 10.1002/ajmg.a.35285] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 12/17/2011] [Indexed: 11/09/2022]
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Matabosch X, Ying L, Serra M, Wassif CA, Porter FD, Shackleton C, Watson G. Increasing cholesterol synthesis in 7-dehydrosterol reductase (DHCR7) deficient mouse models through gene transfer. J Steroid Biochem Mol Biol 2010; 122:303-9. [PMID: 20800683 PMCID: PMC2966472 DOI: 10.1016/j.jsbmb.2010.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 08/18/2010] [Accepted: 08/19/2010] [Indexed: 02/07/2023]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is caused by deficiency in the terminal step of cholesterol biosynthesis: the conversion of 7-dehydrocholesterol (7DHC) to cholesterol (C), catalyzed by 7-dehydrocholesterol reductase (DHCR7). This disorder exhibits several phenotypic traits including dysmorphia and mental retardation with a broad range of severity. There are few proven treatment options. That most commonly used is a high cholesterol diet that seems to enhance the quality of life and improve behavioral characteristics of patients, although these positive effects are controversial. The goal of our study was to investigate the possibility of restoring DHCR7 activity by gene transfer. We constructed an adeno-associated virus (AAV) vector containing the DHCR7 gene. After we infused this vector into affected mice, the introduced DHCR7 gene could be identified in liver, mRNA was expressed and a functional enzyme was produced. Evidence of functionality came from the ability to partially normalize the serum ratio of 7DHC/C in treated animals, apparently by increasing cholesterol production with concomitant decrease in 7DHC precursor. By 5 weeks after treatment the mean ratio (for 7 animals) had fallen to 0.05 while the ratio for untreated littermate controls had risen to 0.14. This provides proof of principle that gene transfer can ameliorate the genetic defect causing SLOS and provides a new experimental tool for studying the pathogenesis of this disease. If effective in humans, it might also offer a possible alternative to exogenous cholesterol therapy. However, it would not offer a complete cure for the disorder as many of the negative implications of defective synthesis are already established during prenatal development.
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Affiliation(s)
- Xavier Matabosch
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way Oakland, 94609, California
| | - Lee Ying
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way Oakland, 94609, California
| | - Montserrat Serra
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way Oakland, 94609, California
| | - Christopher A. Wassif
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892
| | - Forbes D. Porter
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892
| | - Cedric Shackleton
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way Oakland, 94609, California
- Center for Endocrinology, Diabetes and Metabolism (CEDAM), Institute of Biomedical Research, University of Birmingham, Wolfson Drive, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Gordon Watson
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr Way Oakland, 94609, California
- Address for correspondence: Dr Gordon Watson, Children's Hospital Oakland Research Institute, 5700 Martin Luther King Way, Oakland, CA 94609, United States of America, Tel (001) 510 450 7665, Fax (001)510 450 7910,
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Marcos J, Shackleton CH, Buddhikot MM, Porter FD, Watson GL. Cholesterol biosynthesis from birth to adulthood in a mouse model for 7-dehydrosterol reductase deficiency (Smith-Lemli-Opitz syndrome). Steroids 2007; 72:802-8. [PMID: 17714750 PMCID: PMC2911235 DOI: 10.1016/j.steroids.2007.07.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 04/28/2007] [Accepted: 07/06/2007] [Indexed: 10/23/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is caused by deficiency in the terminal step of cholesterol biosynthesis, which is catalyzed by 7-dehydrocholesterol reductase (DHCR7). The disorder exhibits several phenotypic traits including dysmorphia and mental retardation with a broad range of severity. Pathogenesis of SLOS is complex due to multiple roles of cholesterol and may be further complicated by unknown effects of aberrant metabolites that arise when 7-dehydrocholesterol (7-DHC), the substrate for DHCR7, accumulates. A viable mouse model for SLOS has recently been developed, and here we characterize cholesterol metabolism in this model with emphasis on changes during the first few weeks of postnatal development. Cholesterol and 7-DHC were measured in "SLOS" mice and compared with measurements in normal mice. SLOS mice had measurable levels of 7-DHC at all ages tested (up to 1 year), while 7-DHC was below the threshold for detection in normal mice. In perinatal to weaning age SLOS mice, cholesterol and 7-DHC levels changed dramatically. Changes in brain and liver were independent; in brain cholesterol increased several fold while 7-DHC remained relatively constant, but in liver cholesterol first increased then decreased again while 7-DHC first decreased then increased. In older SLOS animals the ratio of 7-DHC/cholesterol, which is an index of biochemical severity, tended to approach, but not reach, normal. While these mice provide the best available genetic animal model for the study of SLOS pathogenesis and treatment, they probably will be most useful at early ages when the metabolic effects of the mutations are most dramatic. To correlate any experimental treatment with improved sterol metabolism will require age-matched controls. Finally, determining the mechanism by which these "SLOS" mice tend to normalize may provide insight into the future development of therapy.
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Affiliation(s)
- Josep Marcos
- Children’s Hospital Oakland Research Institute, Oakland, CA, USA
| | | | | | | | - Gordon L. Watson
- Children’s Hospital Oakland Research Institute, Oakland, CA, USA
- *Corresponding author: Gordon Watson, Ph.D. Children’s Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland, CA 94609-1673, 510-450-7665 (voice) 10-450-7910 (fax),
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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] [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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Scalco FB, Otto PA, Brunetti IL, Cruzes VM, Moretti-Ferreira D. Smith-Lemli-Opitz syndrome: clinical and biochemical findings in Brazilian patients. Genet Mol Biol 2006. [DOI: 10.1590/s1415-47572006000300003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Nowaczyk MJM, Waye JS, Douketis JD. DHCR7 mutation carrier rates and prevalence of the RSH/Smith-Lemli-Opitz syndrome: Where are the patients? Am J Med Genet A 2006; 140:2057-62. [PMID: 16906538 DOI: 10.1002/ajmg.a.31413] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
RSH/Smith-Lemli-Opitz (SLOS) is an inborn error of metabolism with protean manifestations. Its exact incidence and prevalence are not known; however, the carrier rate for the most frequently occurring mutation, the null mutation IVS8-1G > C, is approximately 1 in 100 for the Caucasian population in North America (1%) and possibly as high as 1 in 50 to 1 in 30 in Central European populations (2-3.3%). Based on the allele frequencies and the proportion of this mutation observed in various patient populations, the expected incidence of RSH/SLOS in those populations was calculated and reported to be between 1 in 1,590 and 1 in 17,000. However, around the world the observed prevalence and incidence are much lower than those calculated from the individual mutation carrier rates observed in any given population. The discrepancy between the expected incidence and prevalence can be explained only in part by the neonatal and infancy deaths of the most severely affected children with RSH/SLOS and the under ascertainment of mild and atypical cases at the mild end of the spectrum. RSH/SLOS may be responsible for a high number of miscarriages. Recent observations estimate the prevalence of SLOS at 16 weeks of gestation as similar to that observed at birth (approximately 1 in 60,000) suggesting that either reduced fertility of carrier couples or losses of affected embryos or fetuses in the first trimester play a significant role in reducing the second trimester prevalence of RSH/SLOS. It is possible that the estimates of carrier rates based on population screening for the most commonly occurring mutations may not reflect the true carrier rates in the population. In order to reconcile the above-mentioned paradoxes, we propose a model based on a higher than observed carrier frequency of the most common mutation and on very high fetal loss of homozygotes for that mutation.
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Craigie RJ, Ba'ath M, Fryer A, Baillie C. Surgical implications of the Smith-Lemli-Opitz syndrome. Pediatr Surg Int 2005; 21:482-4. [PMID: 15834578 DOI: 10.1007/s00383-005-1415-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/21/2004] [Indexed: 11/30/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a syndrome of rare multiple congenital anomalies/mental retardation associated with low plasma cholesterol levels. Prior to receiving the diagnosis of SLOS, affected children may present as a neonatal surgical emergency with ambiguous genitalia, Hirschsprung's disease, and pyloric stenosis. We present two fatal cases of SLOS with near-total Hirschsprung's disease; the surgical, anaesthetic, and medical aspects of the cases are discussed, and a literature review is presented.
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Affiliation(s)
- R J Craigie
- Department of Paediatric Surgery, Royal Liverpool Children's NHS Trust, Alder Hey Hospital, Eaton Road, Liverpool, L12 2AP, UK
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Wassif CA, Krakowiak PA, Wright BS, Gewandter JS, Sterner AL, Javitt N, Yergey AL, Porter FD. Residual cholesterol synthesis and simvastatin induction of cholesterol synthesis in Smith-Lemli-Opitz syndrome fibroblasts. Mol Genet Metab 2005; 85:96-107. [PMID: 15896653 DOI: 10.1016/j.ymgme.2004.12.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Revised: 12/21/2004] [Accepted: 12/22/2004] [Indexed: 11/17/2022]
Abstract
Smith-Lemli-Opitz syndrome (RSH/SLOS) is an autosomal recessive, malformation syndrome caused by mutations in the 3beta-hydroxysterol delta7-reductase gene (DHCR7). DHCR7 catalyzes the reduction of 7-dehydrocholesterol (7DHC) to cholesterol. We report the mutation analysis and determination of residual cholesterol synthesis in 47 SLOS patients, and the effects of treatment of SLOS skin fibroblasts with simvastatin. Using deuterium labeling we have quantified the amount of synthesized cholesterol and 7DHC in homozygote, heterozygote, and control fibroblast cell lines. In SLOS fibroblasts, the fraction of synthesized cholesterol to total sterol synthesis ranged from undetectable to over 50%. This establishes that different mutant alleles encode enzymes with varying degrees of residual activity. There was a correlation between increased phenotypic severity and decreased residual cholesterol synthesis (r(2)=0.45, p<0.0001). Simvastatin treatment of SLOS fibroblasts with residual DHCR7 enzymatic activity decreased 7DHC levels and increased cholesterol synthesis. This increase in cholesterol synthesis is due to increased expression of a mutant allele with residual function. Determination of residual enzymatic activity for specific DHCR7 mutant alleles will help in understanding the processes underlying the broad phenotypic spectrum found in this disorder and will be useful in identifying patients who may benefit from simvastatin therapy.
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Affiliation(s)
- Christopher A Wassif
- Heritable Disorders Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
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Cohen D, Pichard N, Tordjman S, Baumann C, Burglen L, Excoffier E, Lazar G, Mazet P, Pinquier C, Verloes A, Héron D. Specific Genetic Disorders and Autism: Clinical Contribution Towards their Identification. J Autism Dev Disord 2005; 35:103-16. [PMID: 15796126 DOI: 10.1007/s10803-004-1038-2] [Citation(s) in RCA: 173] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Autism is a heterogeneous disorder that can reveal a specific genetic disease. This paper describes several genetic diseases consistently associated with autism (fragile X, tuberous sclerosis, Angelman syndrome, duplication of 15q11-q13, Down syndrome, San Filippo syndrome, MECP2 related disorders, phenylketonuria, Smith-Magenis syndrome, 22q13 deletion, adenylosuccinate lyase deficiency, Cohen syndrome, and Smith-Lemli-Opitz syndrome) and proposes a consensual and economic diagnostic strategy to help practitioners to identify them. A rigorous initial clinical screening is presented to avoid unnecessary laboratory and imaging studies. Regarding psychiatric nosography, the concept of "syndromal autism"--autism associated with other clinical signs should be promoted because it may help to distinguish patients who warrant a multidisciplinary approach and further investigation.
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Affiliation(s)
- David Cohen
- Service de Psychiatrie de l'Enfant et de l'Adolescent, Groupe Hospitalier Pitié-Salpétrière, Paris.
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Ginat S, Battaile KP, Battaile BC, Maslen C, Gibson KM, Steiner RD. Lowered DHCR7 activity measured by ergosterol conversion in multiple cell types in Smith-Lemli-Opitz syndrome. Mol Genet Metab 2004; 83:175-83. [PMID: 15464432 DOI: 10.1016/j.ymgme.2004.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Revised: 07/01/2004] [Accepted: 07/02/2004] [Indexed: 11/21/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol metabolism characterized by multiple congenital anomalies and mental retardation. SLOS results from mutations in 7-dehydrocholesterol Delta7 reductase (DHCR7), the gene encoding the final enzyme involved in cholesterol biosynthesis. The resulting cholesterol deficiency and excessive 7- and 8-dehydrocholesterol (7-DHC, 8-DHC) in plasma and tissues are almost always diagnostic for SLOS. We measured DHCR7 activity in fibroblasts, amniocytes, and chorionic villi from controls, heterozygotes, and SLOS subjects. The enzyme activity (expressed as percent conversion of substrate) was significantly lower in untransformed fibroblasts from SLOS subjects (4.47%+/-0.72) compared to untransformed fibroblasts from heterozygotes (26.6%+/-4.6, p<0.01) or controls (50.6%+/-5.3, p<0.001). We also measured plasma cholesterol and 7-DHC, determined the severity score and identified DHCR7 mutations for most of the subjects. There was no significant correlation of enzyme activity with severity score, plasma cholesterol level, plasma 7-DHC level, or the 7-DHC:cholesterol ratio. We conclude that even though enzyme activity as measured by the ergosterol assay may not correlate with severity, this assay has the potential to distinguish SLOS cells from carrier or unaffected cells in a variety of cell types, and should prove useful in confirming a diagnosis in atypical cases where sterol levels are equivocal. Additionally, it may be important to measure residual enzyme activity in SLOS subjects being considered for a trial of statins, as this treatment could theoretically be detrimental in subjects with little or no DHCR7 activity. Finally, the data suggest a threshold enzyme activity of 8% conversion, below which disease occurs.
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Affiliation(s)
- Sharon Ginat
- Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA
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Sikora DM, Ruggiero M, Petit-Kekel K, Merkens LS, Connor WE, Steiner RD. Cholesterol supplementation does not improve developmental progress in Smith-Lemli-Opitz syndrome. J Pediatr 2004; 144:783-91. [PMID: 15192627 DOI: 10.1016/j.jpeds.2004.02.036] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Smith-Lemli-Opitz syndrome (SLOS) results in multiple malformations, growth deficiency, and mental retardation. Cholesterol supplementation has been used for several years to treat symptoms of SLOS. We assessed the developmental progress of children and adolescents with SLOS over a 6-year period. STUDY DESIGN Patients with SLOS (n=14) received continuous cholesterol supplementation as part of a longitudinal study. Assessment of their developmental progress in the areas of cognitive, motor, and adaptive skills occurred every 6 to 12 months. The progress of each subject over time and the progress of the group as a whole were analyzed by using a repeated-measures design and multiple t tests. RESULTS Developmental quotients did not improve over time for children with SLOS receiving cholesterol. In addition, baseline cholesterol levels, rather than age when supplementation began or increase in cholesterol levels, best predicted developmental outcome. CONCLUSIONS These results suggest that cholesterol supplementation in its current form does not improve the developmental progress of children and adolescents with SLOS.
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Affiliation(s)
- Darryn M Sikora
- Departments of Pediatrics, Doernbecher Children's Hospital, Portland, Oregon, USA.
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Abstract
PURPOSE OF REVIEW This review covers a group of human malformation syndromes, which are caused by inborn errors of cholesterol synthesis. The Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive, multiple malformation, and mental retardation syndrome that is the prototypical example of this group of disorders. In the 10 years since the biochemical cause of SLOS was identified, other malformation syndromes have been shown to result from defects in this pathway. These include desmosterolosis, lathosterolosis, X-linked dominant chondrodysplasia punctata type 2 (CDPX2), congenital hemidysplasia with ichthyosiform erythroderma and limb defects (CHILD syndrome), hydrops-ectopic calcification-moth-eaten skeletal dysplasia (HEM dysplasia), and some cases of Antley-Bixler syndrome. These disorders represent the first true merging of dysmorphology with biochemical genetics. RECENT FINDINGS Recent studies report the identification of human lathosterolosis patients, indicate that SLOS is a relatively common genetic disorder that may be a major unrecognized cause of fetal loss, suggest that correction of the biochemical defect can improve central nervous system function, and show that perturbed sonic hedgehog signaling due to decreased sterol levels likely underlies some of the malformations in SLOS and lathosterolosis. SUMMARY Recognition of the biochemical defect in these syndromes has given insight into the role that cholesterol plays during normal development, into understanding the pathophysiological processes that underlie the clinical problems found in these disorders, and into developing therapeutic interventions.
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Affiliation(s)
- Forbes D Porter
- Heritable Disorders Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-1830, USA.
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Nowaczyk MJM, Eng B, Waye JS, Farrell SA, Sirkin WL. Fetus with renal agenesis and Smith-Lemli-Opitz syndrome. Am J Med Genet A 2003; 120A:305-7. [PMID: 12833423 DOI: 10.1002/ajmg.a.20004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Maternal Serum Unconjugated Estriol as a Predictor for Smith–Lemli–Opitz Syndrome and Other Fetal Conditions. Obstet Gynecol 2003. [DOI: 10.1097/00006250-200307000-00031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Jira PE, Waterham HR, Wanders RJA, Smeitink JAM, Sengers RCA, Wevers RA. Smith-Lemli-Opitz syndrome and the DHCR7 gene. Ann Hum Genet 2003; 67:269-80. [PMID: 12914579 DOI: 10.1046/j.1469-1809.2003.00034.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Smith-Lemli-Opitz syndrome, a severe developmental disorder associated with multiple congenital anomalies, is caused by a defect of cholesterol biosynthesis. Low cholesterol and high concentrations of its direct precursor, 7-dehydrocholesterol, in plasma and tissues are the diagnostic biochemical hallmarks of the syndrome. The plasma sterol concentrations correlate with severity and disease outcome. Mutations in the DHCR7 gene lead to deficient activity of 7-dehydrocholesterol reductase (DHCR7), the final enzyme of the cholesterol biosynthetic pathway. The human DHCR7 gene is localised on chromosome 11q13 and its structure has been characterized. Ninety-one different mutations in the DHCR7 gene have been published to date. This paper is a review of the clinical, biochemical and molecular genetic aspects.
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Affiliation(s)
- P E Jira
- Department of Pediatrics, University Medical Centre Nijmegen, 6500 HB Nijmegen, the Netherlands
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Cooper MK, Wassif CA, Krakowiak PA, Taipale J, Gong R, Kelley RI, Porter FD, Beachy PA. A defective response to Hedgehog signaling in disorders of cholesterol biosynthesis. Nat Genet 2003; 33:508-13. [PMID: 12652302 DOI: 10.1038/ng1134] [Citation(s) in RCA: 301] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2002] [Accepted: 02/28/2003] [Indexed: 11/08/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS), desmosterolosis and lathosterolosis are human syndromes caused by defects in the final stages of cholesterol biosynthesis. Many of the developmental malformations in these syndromes occur in tissues and structures whose embryonic patterning depends on signaling by the Hedgehog (Hh) family of secreted proteins. Here we report that response to the Hh signal is compromised in mutant cells from mouse models of SLOS and lathosterolosis and in normal cells pharmacologically depleted of sterols. We show that decreasing levels of cellular sterols correlate with diminishing responsiveness to the Hh signal. This diminished response occurs at sterol levels sufficient for normal autoprocessing of Hh protein, which requires cholesterol as cofactor and covalent adduct. We further find that sterol depletion affects the activity of Smoothened (Smo), an essential component of the Hh signal transduction apparatus.
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Affiliation(s)
- Michael K Cooper
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Martínez-Frías ML, Bermejo E, Rodríguez-Pinilla E. Incidence of Smith-Lemli-Opitz syndrome in Ontario, Canada. Am J Med Genet A 2003; 116A:101; author reply 102. [PMID: 12476463 DOI: 10.1002/ajmg.a.10838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Wassif CA, Vied D, Tsokos M, Connor WE, Steiner RD, Porter FD. Cholesterol storage defect in RSH/Smith-Lemli-Opitz syndrome fibroblasts. Mol Genet Metab 2002; 75:325-34. [PMID: 12051964 DOI: 10.1016/s1096-7192(02)00010-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The RSH/Smith-Lemli-Opitz syndrome (SLOS) is a multiple malformation/mental retardation syndrome caused by an inborn error of cholesterol synthesis. Mutations in the 3beta-hydroxysteroid Delta(7)-reductase gene result in impaired enzymatic reduction of 7-dehydrocholesterol (7-DHC) to cholesterol. Cells obtain cholesterol by either de novo synthesis or from exogenous sources by the binding and uptake of low density lipoprotein (LDL) particles. Because de novo synthesis of cholesterol is impaired in SLOS, current investigational therapy for SLOS consists of dietary cholesterol supplementation. However, the potential effects of elevated intracellular levels of 7-DHC on intracellular LDL metabolism have not been described. We now report that in addition to the primary defect in de novo cholesterol synthesis, SLOS fibroblasts have a secondary defect of LDL cholesterol metabolism. Staining of fibroblasts with filipin, a fluorescent polyene antibiotic which binds unesterified sterols, shows that SLOS fibroblasts accumulate unesterified sterols. Further studies show that this increased filipin staining was due to an abnormal accumulation of LDL derived cholesterol rather than due to storage of endogenously synthesized 7-dehydrocholesterol (7-DHC). We have also found that SLOS fibroblasts failed to degrade LDL at a normal rate, and examination of SLOS fibroblasts by electron microscopy demonstrated the formation of lysosomal inclusions similar to that seen in Niemann-Pick type C (NPC) cells. We propose that 7-DHC may directly or indirectly inhibit the function of the NPC protein through its sterol-sensing domain (SSD), and that 7-DHC may perturb the function of other SSD containing proteins in SLOS.
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Affiliation(s)
- Christopher A Wassif
- Unit on Molecular Dysmorphology, Heritable Disorders Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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Yagel S, Imbar T, Valsky DV. Re: outcome of pregnancy in chromosomally normal fetuses with increased nuchal translucency in the first trimester. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2002; 19:417-421. [PMID: 11952979 DOI: 10.1046/j.1469-0705.2002.00533_4.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Prasad C, Marles S, Prasad AN, Nikkel S, Longstaffe S, Peabody D, Eng B, Wright S, Waye JS, Nowaczyk MJM. Smith-Lemli-Opitz syndrome: new mutation with a mild phenotype. AMERICAN JOURNAL OF MEDICAL GENETICS 2002; 108:64-8. [PMID: 11857552 DOI: 10.1002/ajmg.10211] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) (Online Mendelian Inheritance in Man, OMIM, 2001, http://www.ncbi.nlm.nih.gov/omim/ for SLOS, MIM 270400) is an autosomal recessive disorder of cholesterol biosynthesis caused by mutations of the 3beta-hydroxysterol Delta(7)-reductase gene, DHCR7. We report on a female infant with an exceptionally mild phenotype of SLOS, in whom molecular studies identified a new mutation in DHCR7. The proposita initially presented with feeding difficulties, failure to thrive, hypotonia, mild developmental delay, and oral tactile aversion. She had minor facial anomalies and 2-3 syndactyly of her toes in both feet. The plasma cholesterol was borderline low at 2.88 mmol/L (normal 2.97-4.40 mmol/L). Elevated plasma 7-dehydrocholesterol level of 200.0 micromol/L confirmed the clinical diagnosis of SLOS. Molecular analysis demonstrated compound heterozygosity for IVS8-1G -->C and Y280C, a new missense mutation in DHCR7. Since the other mutation in this patient is a known null mutation, this newly discovered mutation is presumably associated with significant residual enzyme activity and milder expression of clinical phenotype.
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Affiliation(s)
- Chitra Prasad
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Canada
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Current Awareness. Prenat Diagn 2001. [DOI: 10.1002/pd.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
Over the past few years, the number of identified inborn errors of cholesterol biosynthesis has increased significantly. The first inborn error of cholesterol biosynthesis to be characterized, in the mid 1980s, was mevalonic aciduria. In 1993, Irons et al. ( 1 ) (M. Irons, E. R. Elias, G. Salen, G. S. Tint, and A. K. Batta, Lancet 341:1414, 1993) reported that Smith-Lemli-Opitz syndrome, a classic autosomal recessive malformation syndrome, was due to an inborn error of cholesterol biosynthesis. This was the first inborn error of postsqualene cholesterol biosynthesis to be identified, and subsequently additional inborn errors of postsqualene cholesterol biosynthesis have been characterized to various extent. To date, eight inborn errors of cholesterol metabolism have been described in human patients or in mutant mice. The enzymatic steps impaired in these inborn errors of metabolism include mevolonate kinase (mevalonic aciduria as well as hyperimmunoglobulinemia D and periodic fever syndrome), squalene synthase (Ss-/- mouse), 3beta-hydroxysteroid Delta14-reductase (hydrops-ectopic calcification-moth-eaten skeletal dysplasia), 3beta-hydroxysteroid dehydrogenase (CHILD syndrome, bare patches mouse, and striated mouse), 3beta-hydroxysteroid Delta8,Delta7-isomerase (X-linked dominant chondrodysplasia punctata type 2, CHILD syndrome, and tattered mouse), 3beta-hydroxysteroid Delta24-reductase (desmosterolosis) and 3beta-hydroxysteroid Delta7-reductase (RSH/Smith-Lemli-Opitz syndrome and Dhcr7-/- mouse). Identification of the genetic and biochemical defects which give rise to these syndromes has provided the first step in understanding the pathophysiological processes which underlie these malformation syndromes.
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Affiliation(s)
- N A Nwokoro
- Heritable Disorders Branch, National Institutes of Health, Bethesda, Maryland 20892, USA
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32
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Nowaczyk MJ, Siu VM, Krakowiak PA, Porter FD. Adrenal insufficiency and hypertension in a newborn infant with Smith-Lemli-Opitz syndrome. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/ajmg.1545] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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