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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] [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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Boland MR, Tatonetti NP. Investigation of 7-dehydrocholesterol reductase pathway to elucidate off-target prenatal effects of pharmaceuticals: a systematic review. THE PHARMACOGENOMICS JOURNAL 2016; 16:411-29. [PMID: 27401223 PMCID: PMC5028238 DOI: 10.1038/tpj.2016.48] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 04/15/2016] [Accepted: 05/02/2016] [Indexed: 12/18/2022]
Abstract
Mendelian diseases contain important biological information regarding developmental effects of gene mutations that can guide drug discovery and toxicity efforts. In this review, we focus on Smith–Lemli–Opitz syndrome (SLOS), a rare Mendelian disease characterized by compound heterozygous mutations in 7-dehydrocholesterol reductase (DHCR7) resulting in severe fetal deformities. We present a compilation of SLOS-inducing DHCR7 mutations and the geographic distribution of those mutations in healthy and diseased populations. We observed that several mutations thought to be disease causing occur in healthy populations, indicating an incomplete understanding of the condition and highlighting new research opportunities. We describe the functional environment around DHCR7, including pharmacological DHCR7 inhibitors and cholesterol and vitamin D synthesis. Using PubMed, we investigated the fetal outcomes following prenatal exposure to DHCR7 modulators. First-trimester exposure to DHCR7 inhibitors resulted in outcomes similar to those of known teratogens (50 vs 48% born-healthy). DHCR7 activity should be considered during drug development and prenatal toxicity assessment.
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Affiliation(s)
- M R Boland
- Department of Biomedical Informatics, Columbia University, New York, NY, USA.,Observational Health Data Sciences and Informatics, Columbia University, New York, NY, USA
| | - N P Tatonetti
- Department of Biomedical Informatics, Columbia University, New York, NY, USA.,Observational Health Data Sciences and Informatics, Columbia University, New York, NY, USA.,Department of Systems Biology, Columbia University, New York, NY, USA.,Department of Medicine, Columbia University, New York, NY, USA
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3
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Prabhu AV, Luu W, Sharpe LJ, Brown AJ. Cholesterol-mediated Degradation of 7-Dehydrocholesterol Reductase Switches the Balance from Cholesterol to Vitamin D Synthesis. J Biol Chem 2016; 291:8363-73. [PMID: 26887953 DOI: 10.1074/jbc.m115.699546] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Indexed: 01/08/2023] Open
Abstract
Cholesterol is detrimental to human health in excess but is also essential for normal embryogenesis. Hence, enzymes involved in its synthesis possess many layers of regulation to achieve balanced cholesterol levels. 7-Dehydrocholesterol reductase (DHCR7) is the terminal enzyme of cholesterol synthesis in the Kandutsch-Russell pathway, converting 7-dehydrocholesterol (7DHC) to cholesterol. In the absence of functional DHCR7, accumulation of 7DHC and a lack of cholesterol production leads to the devastating developmental disorder, Smith-Lemli-Opitz syndrome. This study identifies that statin treatment can ameliorate the low DHCR7 expression seen with common Smith-Lemli-Opitz syndrome mutations. Furthermore, we show that wild-type DHCR7 is also relatively labile. In an example of end-product inhibition, cholesterol accelerates the proteasomal degradation of DHCR7, resulting in decreased protein levels and activity. The loss of enzymatic activity results in the accumulation of the substrate 7DHC, which leads to an increased production of vitamin D. Thus, these findings highlight DHCR7 as an important regulatory switch between cholesterol and vitamin D synthesis.
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Affiliation(s)
- Anika V Prabhu
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Winnie Luu
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Laura J Sharpe
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andrew J Brown
- From the School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales 2052, Australia
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4
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Waterham HR, Hennekam RCM. Mutational spectrum of Smith-Lemli-Opitz syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2012; 160C:263-84. [PMID: 23042628 DOI: 10.1002/ajmg.c.31346] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS; OMIM #270400) is an autosomal recessive malformation syndrome characterized by a large spectrum of morphogenic and congenital anomalies. SLOS is caused by mutations in the DHCR7 gene, which encodes 7-dehydrocholesterol reductase, the enzyme that catalyzes the final step in cholesterol biosynthesis. We report on 154 currently known mutations in DHCR7 identified in patients affected with SLOS and discuss their coding consequences. These 154 mutations include 130 missense, 8 nonsense, 8 deletions, 2 insertions, 1 indel, and 5 splice site mutations. Using information available from published case reports and from patients identified in our clinical diagnostic laboratory, we analyzed correlations between genotype, clinical presentation and 7-dehydrocholesterol level.
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Affiliation(s)
- Hans R Waterham
- Laboratory Genetic Metabolic Diseases (F0-222), Academic Medical Center, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
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5
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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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6
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Edison R, Muenke M. The interplay of genetic and environmental factors in craniofacial morphogenesis: holoprosencephaly and the role of cholesterol. Clin Genet 2008. [DOI: 10.1111/j.1399-0004.2003.tb02302.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Mild Smith-Lemli-Opitz syndrome: further delineation of 5 Polish cases and review of the literature. Eur J Med Genet 2007; 51:124-40. [PMID: 18249054 DOI: 10.1016/j.ejmg.2007.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2007] [Accepted: 11/23/2007] [Indexed: 11/30/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder caused by reduced activity of 7-dehydrocholesterol reductase, resulting in an increased concentrations of 7-dehydrocholesterol and 8-dehydrocholesterol in body fluids and tissues. Phenotypically it is characterized by wide range of abnormalities, from mild to lethal forms what causes difficulties in its clinical diagnostics. To further delineate the physical spectrum of the mild form of Smith-Lemli-Opitz syndrome, especially with regard to genotype-phenotype correlation, we describe 5 Polish patients with mild phenotype (one with novel mutation in DHCR7 gene and four published before) and analyze 18 other cases from the literature. As the conclusion we give recommendation for tests toward SLOS in cases with "idiopathic" intellectual impairment and/or behavioral anomalies, as well as in biochemically doubtful but clinically fitting cases with overall gestalt and history of this syndrome.
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Grenier D, Elliott EJ, Zurynski Y, Rodrigues Pereira R, Preece M, Lynn R, von Kries R, Zimmermann H, Dickson NP, Virella D. Beyond counting cases: public health impacts of national Paediatric Surveillance Units. Arch Dis Child 2007; 92:527-33. [PMID: 17158859 PMCID: PMC2066170 DOI: 10.1136/adc.2006.097451] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/27/2006] [Indexed: 11/04/2022]
Abstract
Paediatric Surveillance Units (PSUs) have been established in 14 countries and facilitate national, prospective, active surveillance for a range of conditions, with monthly reporting by child health specialists. The International Network of Paediatric Surveillance Units (INoPSU) was established in 1998 and facilitates international collaboration among member PSUs and allows for sharing of resources, simultaneous data collection and hence comparison of data from different geographical regions. The impact of data collected by PSUs, both individually and collectively as members of INoPSU, on public health outcomes, clinical care and research is described.
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Affiliation(s)
- D Grenier
- Canadian Paediatric Surveillance Program, University of Ottawa and Children's Hospital of Eastern Ontario, Ottawa, Canada
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9
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Tadjuidje E, Hollemann T. Cholesterol homeostasis in development: the role of Xenopus 7-dehydrocholesterol reductase (Xdhcr7) in neural development. Dev Dyn 2006; 235:2095-110. [PMID: 16752377 DOI: 10.1002/dvdy.20860] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
7-dehydrocholesterol reductase (7-Dhcr) catalyses the final step in the pathway of cholesterol biosynthesis. Human patients with inborn errors of 7-Dhcr (Smith-Lemli-Opitz-Syndrome) have elevated serum levels of 7-dehydrocholesterol but low levels of cholesterol, which in phenotypical terms can result in growth retardation, craniofacial abnormalities including cleft palate, and reduced metal abilities. This study reports the isolation and molecular characterisation of 7-dehydrocholesterol reductase (Xdhcr7) from Xenopus laevis. During early embryonic development, the expression of Xdhcr7 is first of all spatially restricted to the Spemann's organizer and later to the notochord. In both tissues, Xdhcr7 is coexpressed with Sonic hedgehog (Shh), which itself is cholesterol-modified during autoproteolytic cleavage. Data from Xdhcr7 overexpression and knockdown experiments reveals that a tight control of cholesterol synthesis is particularly important for proper development of the central and peripheral nervous system.
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Affiliation(s)
- Emmanuel Tadjuidje
- University of Halle-Wittenberg, Institut für Physiologische Chemie, Halle/Saale, Germany
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Correa-Cerro LS, Porter FD. 3beta-hydroxysterol Delta7-reductase and the Smith-Lemli-Opitz syndrome. Mol Genet Metab 2005; 84:112-26. [PMID: 15670717 DOI: 10.1016/j.ymgme.2004.09.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2004] [Revised: 09/28/2004] [Accepted: 09/28/2004] [Indexed: 10/26/2022]
Abstract
In the final step of cholesterol synthesis, 7-dehydrocholesterol reductase (DHCR7) reduces the double bond at C7-8 of 7-dehydrocholesterol to yield cholesterol. Mutations of DHCR7 cause Smith-Lemli-Opitz syndrome (SLOS). Over 100 different mutations of DHCR7 have been identified in SLOS patients. SLOS is a classical multiple malformation, mental retardation syndrome, and was the first human malformation syndrome shown to result from an inborn error of cholesterol synthesis. This paper reviews the biochemical, molecular, and mutational aspects of DHCR7.
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Affiliation(s)
- Lina S Correa-Cerro
- Unit on Molecular Dysmorphology, Heritable Disorders Branch, Department of Health and Human Services, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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11
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Mueller C, Patel S, Irons M, Antshel K, Salen G, Tint G, Bay C. Normal cognition and behavior in a Smith-Lemli-Opitz syndrome patient who presented with Hirschsprung disease. Am J Med Genet A 2004; 123A:100-6. [PMID: 14556255 PMCID: PMC1201564 DOI: 10.1002/ajmg.a.20491] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol biosynthesis. It is caused by mutations in the gene encoding the enzyme 7-dehydrocholesterol Delta7-reductase (DHCR7), which catalyzes the final step in cholesterol biosynthesis, usually resulting in cholesterol deficiency. We report a 3.5-year-old girl who has cognition in the low average range and normal behavior, but in whom molecular studies identified two missense mutations in DHCR7: V326L and F284L. She was born at term following an uncomplicated pregnancy and delivery, and presented at 12 days of age with poor feeding, abdominal distention, and jaundice. Colonic biopsy was consistent with Hirschsprung disease. On physical examination she had mild ptosis, a long philtrum, mild micrognathia, a short, upturned nose, and subtle 2,3 syndactyly. Her 7-dehydrocholesterol (7-DHC) level was markedly elevated at 8.7 mg/dl (normal 0.10 +/- 0.05), and her cholesterol level was normal at 61 mg/dl (normal for newborn period 50-80 mg/dl). Karyotype analysis was normal, 46,XX. Breast milk feeding was initiated and continued for 18 months. Cholesterol supplementation was implemented at 100 mg/kg/day at 3 months, which resulted in increased cholesterol levels and reduced dehydrocholesterol levels. Neuropsychological testing has shown functioning in the low average range, between the 14th and 18th centiles when compared to peers. This is markedly higher than most children with SLOS. She has no behavioral problems. MRI and MRS testing of the brain revealed no structural abnormalities. This is in contrast to a recently reported case by Prasad et al. [2002: Am J Med Genet 108:64-68] with a mild phenotype, behavioral problems, and abnormal MRI, who is compound heterozygote for both a null and missense mutation. Our case suggests that patients with severe feeding disorders with or without Hirschprung disease and postnatal onset microcephaly may warrant screening for SLOS.
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Affiliation(s)
- C. Mueller
- Department of Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - S. Patel
- Medical University of South Carolina, Charleston, South Carolina
| | - M. Irons
- Children’s Hospital Boston, Boston, Massachusetts
| | - K. Antshel
- Children’s Hospital Boston, Boston, Massachusetts
| | - G. Salen
- VA Medical Center, East Orange, New Jersey
| | - G.S. Tint
- VA Medical Center, East Orange, New Jersey
| | - C. Bay
- Children’s Hospital Pittsburgh, Pittsburgh, Pennsylvania
- *Correspondence to: C. Bay, Children’s Hospital of Pittsburgh, 3705 Fifth Ave., Pittsburgh, PA 15213. E-mail:
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12
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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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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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Edison R, Muenke M. The interplay of genetic and environmental factors in craniofacial morphogenesis: holoprosencephaly and the role of cholesterol. Congenit Anom (Kyoto) 2003; 43:1-21. [PMID: 12692399 DOI: 10.1111/j.1741-4520.2003.tb01022.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cyclopia, the paradigmatic "face [that] predicts the brain" in severe holoprosencephaly (HPE) (DeMyer et al., 1964), has been recognized since ancient times. Descriptive embryologists and pathologists have noted the continuum of defective separation of the forebrain and loss of central nervous system (CNS) midline structures for more than a century. It has been recognized more recently that inhibitors of cholesterol biosynthesis, whether consumed in native plants by range sheep, or experimentally applied to early embryos, could phenocopy the natural malformation, as could a variety of other teratogens (maternal diabetes, alcohol). Yet it has been less than a decade that the genomic knowledge base and powerful analytic methods have brought the sciences of descriptive, molecular, and genetic embryology within range of each other. In this review, we discuss the clinical presentations and pathogenesis of HPE. We will outline various genetic and teratogenic mechanisms leading to HPE. Lastly, we will attempt to examine the pivotal role of cholesterol and the Sonic Hedgehog (Shh) pathway in this disorder and in normal embryonic forebrain development.
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Affiliation(s)
- Robin Edison
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
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