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Bendixen C, Brosens E, Chung WK. Genetic Diagnostic Strategies and Counseling for Families Affected by Congenital Diaphragmatic Hernia. Eur J Pediatr Surg 2021; 31:472-481. [PMID: 34911129 DOI: 10.1055/s-0041-1740337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Congenital diaphragmatic hernia (CDH) is a relatively common and severe birth defect with variable clinical outcome and associated malformations in up to 60% of patients. Mortality and morbidity remain high despite advances in pre-, intra-, and postnatal management. We review the current literature and give an overview about the genetics of CDH to provide guidelines for clinicians with respect to genetic diagnostics and counseling for families. Until recently, the common practice was (molecular) karyotyping or chromosome microarray if the CDH diagnosis is made prenatally with a 10% diagnostic yield. Undiagnosed patients can be reflexed to trio exome/genome sequencing with an additional diagnostic yield of 10 to 20%. Even with a genetic diagnosis, there can be a range of clinical outcomes. All families with a child with CDH with or without additional malformations should be offered genetic counseling and testing in a family-based trio approach.
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Affiliation(s)
- Charlotte Bendixen
- Department of General, Visceral, Vascular and Thoracic Surgery, Unit of Pediatric Surgery, Universitätsklinikum Bonn, Bonn, Germany
| | - Erwin Brosens
- Department of Pediatric Surgery, Erasmus MC Sophia Children's Hospital, Rotterdam, the Netherlands
| | - Wendy Kay Chung
- Department of Medicine, Columbia University Irving Medical Center, New York, United States.,Department of Pediatrics, Columbia University Irving Medical Center, New York, United States
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2
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Saini A, Almasarweh S, Acosta S, Jayakar P, Janvier M, Wong TC, Salyakina D, Sasaki J. Syndromic Microphthalmia 9: Role of rapid genome sequencing and novel mutations in STRA6 gene. PROGRESS IN PEDIATRIC CARDIOLOGY 2021. [DOI: 10.1016/j.ppedcard.2021.101443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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3
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Sirbu IO, Chiş AR, Moise AR. Role of carotenoids and retinoids during heart development. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158636. [PMID: 31978553 DOI: 10.1016/j.bbalip.2020.158636] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 02/08/2023]
Abstract
The nutritional requirements of the developing embryo are complex. In the case of dietary vitamin A (retinol, retinyl esters and provitamin A carotenoids), maternal derived nutrients serve as precursors to signaling molecules such as retinoic acid, which is required for embryonic patterning and organogenesis. Despite variations in the composition and levels of maternal vitamin A, embryonic tissues need to generate a precise amount of retinoic acid to avoid congenital malformations. Here, we summarize recent findings regarding the role and metabolism of vitamin A during heart development and we survey the association of genes known to affect retinoid metabolism or signaling with various inherited disorders. A better understanding of the roles of vitamin A in the heart and of the factors that affect retinoid metabolism and signaling can help design strategies to meet nutritional needs and to prevent birth defects and disorders associated with altered retinoid metabolism. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.
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Affiliation(s)
- Ioan Ovidiu Sirbu
- Biochemistry Department, Victor Babes University of Medicine and Pharmacy, Eftimie Murgu Nr. 2, 300041 Timisoara, Romania; Timisoara Institute of Complex Systems, V. Lucaciu 18, 300044 Timisoara, Romania.
| | - Aimée Rodica Chiş
- Biochemistry Department, Victor Babes University of Medicine and Pharmacy, Eftimie Murgu Nr. 2, 300041 Timisoara, Romania
| | - Alexander Radu Moise
- Medical Sciences Division, Northern Ontario School of Medicine, Sudbury, ON P3E 2C6, Canada; Department of Chemistry and Biochemistry, Biology and Biomolecular Sciences Program, Laurentian University, Sudbury, ON P3E 2C6, Canada.
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4
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Nedelec B, Rozet JM, Fares Taie L. Genetic architecture of retinoic-acid signaling-associated ocular developmental defects. Hum Genet 2019; 138:937-955. [DOI: 10.1007/s00439-019-02052-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 07/23/2019] [Indexed: 12/14/2022]
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Wang S, Moise AR. Recent insights on the role and regulation of retinoic acid signaling during epicardial development. Genesis 2019; 57:e23303. [PMID: 31066193 PMCID: PMC6682438 DOI: 10.1002/dvg.23303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 12/18/2022]
Abstract
The vitamin A metabolite, retinoic acid, carries out essential and conserved roles in vertebrate heart development. Retinoic acid signals via retinoic acid receptors (RAR)/retinoid X receptors (RXRs) heterodimers to induce the expression of genes that control cell fate specification, proliferation, and differentiation. Alterations in retinoic acid levels are often associated with congenital heart defects. Therefore, embryonic levels of retinoic acid need to be carefully regulated through the activity of enzymes, binding proteins and transporters involved in vitamin A metabolism. Here, we review evidence of the complex mechanisms that control the fetal uptake and synthesis of retinoic acid from vitamin A precursors. Next, we highlight recent evidence of the role of retinoic acid in orchestrating myocardial compact zone growth and coronary vascular development.
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Affiliation(s)
- Suya Wang
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Alexander R. Moise
- Medical Sciences Division, Northern Ontario School of Medicine, Sudbury, ON P3E 2C6, Canada
- Departments of Chemistry and Biochemistry, and Biology and Biomolecular Sciences Program, Laurentian University, Sudbury, ON, P3E 2C6 Canada
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS, 66045, USA
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Slavotinek A. Genetics of anophthalmia and microphthalmia. Part 2: Syndromes associated with anophthalmia-microphthalmia. Hum Genet 2018; 138:831-846. [PMID: 30374660 DOI: 10.1007/s00439-018-1949-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 10/20/2018] [Indexed: 12/12/2022]
Abstract
As new genes for A/M are identified in the genomic era, the number of syndromes associated with A/M has greatly expanded. In this review, we provide a brief synopsis of the clinical presentation and molecular genetic etiology of previously characterized pathways involved in A/M, including the Sex-determining region Y-box 2 (SOX2), Orthodenticle Homeobox 2 (OTX2) and Paired box protein-6 (PAX6) genes, and the Stimulated by retinoic acid gene 6 homolog (STRA6), Aldehyde Dehydrogenase 1 Family Member A3 (ALDH1A3), and RA Receptor Beta (RARβ) genes that are involved in retinoic acid synthesis. Less common genetic causes of A/M, including genes involved in BMP signaling [Bone Morphogenetic Protein 4 (BMP4), Bone Morphogenetic Protein 7 (BMP7) and SPARC-related modular calcium-binding protein 1 (SMOC1)], genes involved in the mitochondrial respiratory chain complex [Holocytochrome c-type synthase (HCCS), Cytochrome C Oxidase Subunit 7B (COX7B), and NADH:Ubiquinone Oxidoreductase subunit B11 (NDUFB11)], the BCL-6 corepressor gene (BCOR), Yes-Associated Protein 1 (YAP1) and Transcription Factor AP-2 Alpha (TFAP2α), are more briefly discussed. We also review several recently described genes and pathways associated with A/M, including Smoothened (SMO) that is involved in Sonic hedgehog (SHH) signaling, Structural maintenance of chromosomes flexible hinge domain containing 1 (SMCHD1) and Solute carrier family 25 member 24 (SLC25A24), emphasizing phenotype-genotype correlations and shared pathways where relevant.
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Affiliation(s)
- Anne Slavotinek
- Division of Genetics, Department of Pediatrics, University of California, San Francisco Room RH384C, 1550 4th St, San Francisco, CA, 94143-2711, USA.
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Pasutto F, Flinter F, Rauch A, Reis A. Novel STRA6 null mutations in the original family described with Matthew-Wood syndrome. Am J Med Genet A 2017; 176:134-138. [PMID: 29168296 DOI: 10.1002/ajmg.a.38529] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 10/15/2017] [Indexed: 01/31/2023]
Affiliation(s)
- Francesca Pasutto
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Frances Flinter
- Department of Clinical Genetics, Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich, Switzerland
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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8
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Sadowski S, Chassaing N, Gaj Z, Czichos E, Wilczynski J, Nowakowska D. Both a frameshift and a missense mutation of theSTRA6gene observed in an infant with the Matthew-Wood syndrome. Birth Defects Res 2017; 109:251-253. [DOI: 10.1002/bdra.23465] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 09/16/2015] [Accepted: 09/28/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Samantha Sadowski
- Obstetrics, Gynecology, and Gynecological Oncology, Medical University of Lodz; Lodz Poland
| | - Nicolas Chassaing
- Service de Génétique Médicale, Pavillon Lefebvre EA-455 UPSIII, Hôpital Purpan CHU Toulouse; France
| | - Zuzanna Gaj
- Department of Perinatology and Gynecology; Polish Mother's Memorial Hospital - Research Institute; Lodz Poland
- Scientific Laboratory of Center of Medical Laboratory Diagnostics, Polish Mother's Memorial Hospital - Research Institute; Lodz Poland
| | - Ewa Czichos
- Department of Pathology; Polish Mother's Memorial Hospital - Research Institute; Lodz Poland
| | - Jan Wilczynski
- Duchess Anna Mazowiecka Public Teaching Hospital; Warsaw Poland
| | - Dorota Nowakowska
- Obstetrics, Gynecology, and Gynecological Oncology, Medical University of Lodz; Lodz Poland
- Department of Perinatology and Gynecology; Polish Mother's Memorial Hospital - Research Institute; Lodz Poland
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Marcadier JL, Mears AJ, Woods EA, Fisher J, Airheart C, Qin W, Beaulieu CL, Dyment DA, Innes AM, Curry CJ. A novel mutation in two Hmong families broadens the range of STRA6-related malformations to include contractures and camptodactyly. Am J Med Genet A 2015; 170A:11-8. [PMID: 26373900 DOI: 10.1002/ajmg.a.37389] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 08/13/2015] [Indexed: 11/06/2022]
Abstract
PDAC (also termed Matthew Wood) syndrome is a rare, autosomal recessive disorder characterized by pulmonary hypoplasia/aplasia, diaphragmatic defects, bilateral anophthalmia, and cardiac malformations. The disorder is caused by mutations in STRA6, an important regulator of vitamin A and retinoic acid metabolism. We describe six cases from four families of Hmong ancestry, seen over a 30 years period in California. These include: (i) consanguineous siblings with a combination of bilateral anophthalmia, diaphragmatic abnormalities, truncus arteriosus, and/or pulmonary agenesis/hypoplasia; (ii) a singleton fetus with bilateral anophthalmia, pulmonary agenesis, cardiac malformation, and renal hypoplasia; (iii) a sibling pair with a combination of antenatal contractures, camptodactyly, fused palpebral fissures, pulmonary agenesis, and/or truncus arteriosus; (iv) a fetus with bilateral anophthalmia, bushy eyebrows, pulmonary agenesis, heart malformation, and abnormal hand positioning. The phenotypic spectrum of PDAC syndrome has until now not included contractures or camptodactyly. Sequencing of STRA6 in unrelated members of families three and four identified a novel, shared homozygous splice site alteration (c.113 + 3_4delAA) that is predicted to be pathogenic. We hypothesize this may represent a unique disease allele in the Hmong. We also provide a focused review of all published PDAC syndrome cases with confirmed or inferred STRA6 mutations, illustrating the phenotypic and molecular variability that characterizes this disorder.
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Affiliation(s)
- Julien L Marcadier
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - Alan J Mears
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Jamie Fisher
- Genetic Medicine Central California, Fresno, California
| | - Cory Airheart
- Community Perinatology Medical Group, Fresno, California
| | - Wen Qin
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Chandree L Beaulieu
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - David A Dyment
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada
| | - A Micheil Innes
- Department of Medical Genetics and Alberta Children's Hospital Research Institute for Child and Maternal Health, University of Calgary, Calgary, Alberta, Canada
| | - Cynthia J Curry
- Genetic Medicine Central California, Fresno, California.,Department of Pediatrics, University of California, San Francisco, California
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Vitamin A Transport Mechanism of the Multitransmembrane Cell-Surface Receptor STRA6. MEMBRANES 2015; 5:425-53. [PMID: 26343735 PMCID: PMC4584289 DOI: 10.3390/membranes5030425] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 08/24/2015] [Indexed: 12/18/2022]
Abstract
Vitamin A has biological functions as diverse as sensing light for vision, regulating stem cell differentiation, maintaining epithelial integrity, promoting immune competency, regulating learning and memory, and acting as a key developmental morphogen. Vitamin A derivatives have also been used in treating human diseases. If vitamin A is considered a drug that everyone needs to take to survive, evolution has come up with a natural drug delivery system that combines sustained release with precise and controlled delivery to the cells or tissues that depend on it. This "drug delivery system" is mediated by plasma retinol binding protein (RBP), the principle and specific vitamin A carrier protein in the blood, and STRA6, the cell-surface receptor for RBP that mediates cellular vitamin A uptake. The mechanism by which the RBP receptor absorbs vitamin A from the blood is distinct from other known cellular uptake mechanisms. This review summarizes recent progress in elucidating the fundamental molecular mechanism mediated by the RBP receptor and multiple newly discovered catalytic activities of this receptor, and compares this transport system with retinoid transport independent of RBP/STRA6. How to target this new type of transmembrane receptor using small molecules in treating diseases is also discussed.
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11
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Downregulation of STRA6 in adipocytes and adipose stromovascular fraction in obesity and effects of adipocyte-specific STRA6 knockdown in vivo. Mol Cell Biol 2014; 34:1170-86. [PMID: 24421389 DOI: 10.1128/mcb.01106-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
To investigate the mechanisms by which elevated retinol-binding protein 4 (RBP4) causes insulin resistance, we studied the role of the high-affinity receptor for RBP4, STRA6 (stimulated by retinoic acid), in insulin resistance and obesity. In high-fat-diet-fed and ob/ob mice, STRA6 expression was decreased 70 to 95% in perigonadal adipocytes and both perigonadal and subcutaneous adipose stromovascular cells. To determine whether downregulation of STRA6 in adipocytes contributes to insulin resistance, we generated adipose-Stra6(-/-) mice. Adipose-Stra6(-/-) mice fed chow had decreased body weight, fat mass, leptin levels, insulin levels, and adipocyte number and increased expression of brown fat-selective markers in white adipose tissue. When fed a high-fat diet, these mice had a mild improvement in insulin sensitivity at an age when adiposity was unchanged. STRA6 has been implicated in retinol uptake, but retinol uptake and the expression of retinoid homeostatic genes (encoding retinoic acid receptor β [RARβ], CYP26A1, and lecithin retinol acyltransferase) were not altered in adipocytes from adipose-Stra6(-/-) mice, indicating that retinoid homeostasis was maintained with STRA6 knockdown. Thus, STRA6 reduction in adipocytes in adipose-Stra6(-/-) mice fed chow resulted in leanness, which may contribute to their increased insulin sensitivity. However, in wild-type mice with high-fat-diet-induced obesity and in ob/ob mice, the marked downregulation of STRA6 in adipocytes and adipose stromovascular cells does not compensate for obesity-associated insulin resistance.
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12
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Yahyavi M, Abouzeid H, Gawdat G, de Preux AS, Xiao T, Bardakjian T, Schneider A, Choi A, Jorgenson E, Baier H, El Sada M, Schorderet DF, Slavotinek AM. ALDH1A3 loss of function causes bilateral anophthalmia/microphthalmia and hypoplasia of the optic nerve and optic chiasm. Hum Mol Genet 2013; 22:3250-8. [PMID: 23591992 DOI: 10.1093/hmg/ddt179] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The major active retinoid, all-trans retinoic acid, has long been recognized as critical for the development of several organs, including the eye. Mutations in STRA6, the gene encoding the cellular receptor for vitamin A, in patients with Matthew-Wood syndrome and anophthalmia/microphthalmia (A/M), have previously demonstrated the importance of retinol metabolism in human eye disease. We used homozygosity mapping combined with next-generation sequencing to interrogate patients with anophthalmia and microphthalmia for new causative genes. We used whole-exome and whole-genome sequencing to study a family with two affected brothers with bilateral A/M and a simplex case with bilateral anophthalmia and hypoplasia of the optic nerve and optic chiasm. Analysis of novel sequence variants revealed homozygosity for two nonsense mutations in ALDH1A3, c.568A>G, predicting p.Lys190*, in the familial cases, and c.1165A>T, predicting p.Lys389*, in the simplex case. Both mutations predict nonsense-mediated decay and complete loss of function. We performed antisense morpholino (MO) studies in Danio rerio to characterize the developmental effects of loss of Aldh1a3 function. MO-injected larvae showed a significant reduction in eye size, and aberrant axonal projections to the tectum were noted. We conclude that ALDH1A3 loss of function causes anophthalmia and aberrant eye development in humans and in animal model systems.
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Affiliation(s)
- Mani Yahyavi
- Division of Genetics, Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143-0748, USA
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Chassaing N, Ragge N, Kariminejad A, Buffet A, Ghaderi-Sohi S, Martinovic J, Calvas P. Mutation analysis of the STRA6 gene in isolated and non-isolated anophthalmia/microphthalmia. Clin Genet 2012; 83:244-50. [PMID: 22686418 DOI: 10.1111/j.1399-0004.2012.01904.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 05/25/2012] [Accepted: 06/04/2012] [Indexed: 12/14/2022]
Abstract
PDAC syndrome [Pulmonary hypoplasia/agenesis, Diaphragmatic hernia/eventration, Anophthalmia/microphthalmia (A/M) and Cardiac Defect] is a condition associated with recessive mutations in the STRA6 gene in some of these patients. Recently, cases with isolated anophthalmia have been associated with STRA6 mutations. To determine the minimal findings associated with STRA6 mutations, we performed mutation analysis of the STRA6 gene in 28 cases with anophthalmia. In 7 of the cases the anophthalmia was isolated, in 14 cases it was associated with one of the major features included in PDAC and 7 had other abnormalities. Mutations were identified in two individuals: one with bilateral anophthalmia and some features included in PDAC, who was a compound heterozygote for a missense mutation and a large intragenic deletion, and the second case with all the major features of PDAC and who had a homozygous splicing mutation. This study suggests that STRA6 mutations are more likely to be identified in individuals with A/M and other abnormalities included in the PDAC spectrum, rather than in isolated A/M cases.
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Affiliation(s)
- N Chassaing
- Department of Medical Genetics, CHU Toulouse, Purpan Hospital, 31059, Toulouse, France.
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Ng WY, Pasutto F, Bardakjian TM, Wilson MJ, Watson G, Schneider A, Mackey DA, Grigg JR, Zenker M, Jamieson RV. A puzzle over several decades: eye anomalies with FRAS1 and STRA6 mutations in the same family. Clin Genet 2012; 83:162-8. [PMID: 22283518 DOI: 10.1111/j.1399-0004.2012.01851.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Fraser syndrome (FS) and microphthalmia syndromic 9 (MCOPS9) are autosomal recessive conditions with distinct, and some overlapping features affecting the ocular, respiratory and cardiac systems. Mutations in FRAS1 and FREM2 occur in FS, and mutations in STRA6 occur in MCOPS9. We report two sibships, in the same family, where four deceased offspring had ocular, respiratory and cardiac abnormalities. Two sibs with microphthalmia had syndactyly and laryngeal stenosis, suggesting a clinical diagnosis of FS. Our results indicate that they were compound heterozygotes for novel FRAS1 mutations, p.Cys729Phe and p.Leu3813Pro. The other two sibs, first cousins to the first sib pair, had anophthalmia, lung hypoplasia and cardiac anomalies, suggesting a retrospective diagnosis of MCOPS9. Our results indicate compound heterozygous STRA6 mutations, a novel frameshift leading to p.Tyr18* and a p.Thr644Met mutation. The one surviving individual from these sibships is heterozygous for the p.Tyr18*STRA6 mutation and has bilateral ocular colobomata and microphthalmia. This work emphasises the need for careful phenotypic characterisation to determine genes for assessment in ocular syndromic conditions. It also indicates that heterozygous STRA6 mutations may rarely contribute to microphthalmia and coloboma.
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Affiliation(s)
- W Y Ng
- Eye Genetics Research Group, Children's Medical Research Institute, The Children's Hospital at Westmead, Save Sight Institute, Sydney, Australia
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15
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Slavotinek AM. Eye development genes and known syndromes. Mol Genet Metab 2011; 104:448-56. [PMID: 22005280 PMCID: PMC3224152 DOI: 10.1016/j.ymgme.2011.09.029] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 09/21/2011] [Accepted: 09/21/2011] [Indexed: 11/22/2022]
Abstract
Anophthalmia and microphthalmia (A/M) are significant eye defects because they can have profound effects on visual acuity. A/M is associated with non-ocular abnormalities in an estimated 33-95% of cases and around 25% of patients have an underlying genetic syndrome that is diagnosable. Syndrome recognition is important for targeted molecular genetic testing, prognosis and for counseling regarding recurrence risks. This review provides clinical and molecular information for several of the commonest syndromes associated with A/M: Anophthalmia-Esophageal-Genital syndrome, caused by SOX2 mutations, Anophthalmia and pituitary abnormalities caused by OTX2 mutations, Matthew-Wood syndrome caused by STRA6 mutations, oculofaciocardiodental syndrome and Lenz microphthalmia caused by BCOR mutations, Microphthalmia Linear Skin pigmentation syndrome caused by HCCS mutations, Anophthalmia, pituitary abnormalities, polysyndactyly caused by BMP4 mutations and Waardenburg anophthalmia caused by mutations in SMOC1. In addition, we briefly discuss the ocular and extraocular phenotypes associated with several other important eye developmental genes, including GDF6, VSX2, RAX, SHH, SIX6 and PAX6.
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Affiliation(s)
- Anne M Slavotinek
- Department of Pediatrics, Division of Genetics, University of California, San Francisco, San Francisco, CA 94143-0748, USA.
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Casey J, Kawaguchi R, Morrissey M, Sun H, McGettigan P, Nielsen JE, Conroy J, Regan R, Kenny E, Cormican P, Morris DW, Tormey P, Chróinín MN, Kennedy BN, Lynch S, Green A, Ennis S. First implication of STRA6 mutations in isolated anophthalmia, microphthalmia, and coloboma: a new dimension to the STRA6 phenotype. Hum Mutat 2011; 32:1417-26. [PMID: 21901792 DOI: 10.1002/humu.21590] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 07/25/2011] [Indexed: 11/11/2022]
Abstract
Microphthalmia, anophthalmia, and coloboma (MAC) are structural congenital eye malformations that cause a significant proportion of childhood visual impairments. Several disease genes have been identified but do not account for all MAC cases, suggesting that additional risk loci exist. We used single nucleotide polymorphism (SNP) homozygosity mapping (HM) and targeted next-generation sequencing to identify the causative mutation for autosomal recessive isolated colobomatous microanophthalmia (MCOPCB) in a consanguineous Irish Traveller family. We identified a double-nucleotide polymorphism (g.1157G>A and g.1156G>A; p.G304K) in STRA6 that was homozygous in all of the MCOPCB patients. The STRA6 p.G304K mutation was subsequently detected in additional MCOPCB patients, including one individual with Matthew-Wood syndrome (MWS; MCOPS9). STRA6 encodes a transmembrane receptor involved in vitamin A uptake, a process essential to eye development and growth. We have shown that the G304K mutant STRA6 protein is mislocalized and has severely reduced vitamin A uptake activity. Furthermore, we reproduced the MCOPCB phenotype in a zebrafish disease model by inhibiting retinoic acid (RA) synthesis, suggesting that diminished RA levels account for the eye malformations in STRA6 p.G304K patients. The current study demonstrates that STRA6 mutations can cause isolated eye malformations in addition to the congenital anomalies observed in MWS.
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Affiliation(s)
- Jillian Casey
- School of Medicine and Medical Science, University College Dublin, Belfield, Dublin, Ireland
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Sun H. Membrane receptors and transporters involved in the function and transport of vitamin A and its derivatives. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:99-112. [PMID: 21704730 DOI: 10.1016/j.bbalip.2011.06.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/01/2011] [Accepted: 06/10/2011] [Indexed: 12/12/2022]
Abstract
The eye is the human organ most sensitive to vitamin A deficiency because of vision's absolute and heavy dependence on vitamin A for light perception. Studies of the molecular basis of vision have provided important insights into the intricate mechanistic details of the function, transport and recycling of vitamin A and its derivatives (retinoid). This review focuses on retinoid-related membrane receptors and transporters. Three kinds of mammalian membrane receptors and transporters are discussed: opsins, best known as vitamin A-based light sensors in vision; ABCA4, an ATP-dependent transporter specializes in the transport of vitamin A derivative; and STRA6, a recently identified membrane receptor that mediates cellular uptake of vitamin A. The evolutionary driving forces for their existence and the wide spectrum of human diseases associated with these proteins are discussed. Lessons learned from the study of the visual system might be useful for understanding retinoid biology and retinoid-related diseases in other organ systems as well. This article is part of a Special Issue entitled Retinoid and Lipid Metabolism.
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Affiliation(s)
- Hui Sun
- Department of Physiology, Jules Stein Eye Institute, Brian Research Institute, and Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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D'Ambrosio DN, Clugston RD, Blaner WS. Vitamin A metabolism: an update. Nutrients 2011; 3:63-103. [PMID: 21350678 PMCID: PMC3042718 DOI: 10.3390/nu3010063] [Citation(s) in RCA: 351] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 12/24/2010] [Accepted: 01/11/2011] [Indexed: 12/18/2022] Open
Abstract
Retinoids are required for maintaining many essential physiological processes in the body, including normal growth and development, normal vision, a healthy immune system, normal reproduction, and healthy skin and barrier functions. In excess of 500 genes are thought to be regulated by retinoic acid. 11-cis-retinal serves as the visual chromophore in vision. The body must acquire retinoid from the diet in order to maintain these essential physiological processes. Retinoid metabolism is complex and involves many different retinoid forms, including retinyl esters, retinol, retinal, retinoic acid and oxidized and conjugated metabolites of both retinol and retinoic acid. In addition, retinoid metabolism involves many carrier proteins and enzymes that are specific to retinoid metabolism, as well as other proteins which may be involved in mediating also triglyceride and/or cholesterol metabolism. This review will focus on recent advances for understanding retinoid metabolism that have taken place in the last ten to fifteen years.
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Affiliation(s)
- Diana N D'Ambrosio
- Department of Medicine and Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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Sun H, Kawaguchi R. The membrane receptor for plasma retinol-binding protein, a new type of cell-surface receptor. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2011; 288:1-41. [PMID: 21482409 DOI: 10.1016/b978-0-12-386041-5.00001-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Vitamin A is essential for diverse aspects of life ranging from embryogenesis to the proper functioning of most adult organs. Its derivatives (retinoids) have potent biological activities such as regulating cell growth and differentiation. Plasma retinol-binding protein (RBP) is the specific vitamin A carrier protein in the blood that binds to vitamin A with high affinity and delivers it to target organs. A large amount of evidence has accumulated over the past decades supporting the existence of a cell-surface receptor for RBP that mediates cellular vitamin A uptake. Using an unbiased strategy, this specific cell-surface RBP receptor has been identified as STRA6, a multitransmembrane domain protein with previously unknown function. STRA6 is not homologous to any protein of known function and represents a new type of cell-surface receptor. Consistent with the diverse functions of vitamin A, STRA6 is widely expressed in embryonic development and in adult organ systems. Mutations in human STRA6 are associated with severe pathological phenotypes in many organs such as the eye, brain, heart, and lung. STRA6 binds to RBP with high affinity and mediates vitamin A uptake into cells. This review summarizes the history of the RBP receptor research, its expression in the context of known functions of vitamin A in distinct human organs, structure/function analysis of this new type of membrane receptor, pertinent questions regarding its very existence, and its potential implication in treating human diseases.
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Affiliation(s)
- Hui Sun
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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Pavone ME, Reierstad S, Sun H, Milad M, Bulun SE, Cheng YH. Altered retinoid uptake and action contributes to cell survival in endometriosis. J Clin Endocrinol Metab 2010; 95:E300-9. [PMID: 20702525 PMCID: PMC2968735 DOI: 10.1210/jc.2010-0459] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Retinoic acid (RA) controls multiple biological processes via exerting opposing effects on cell survival. Retinol uptake into cells is controlled by stimulated by RA 6 (STRA6). RA is then produced from retinol in the cytosol. Partitioning of RA between the nuclear receptors RA receptor α and peroxisome-proliferator-activated receptor β/δ is regulated by cytosol-to-nuclear shuttling proteins cellular RA binding protein 2 (CRABP2) and fatty acid binding protein 5 (FABP5), which induce apoptosis or enhance survival, respectively. The roles of these mechanisms in endometrium or endometriosis remain unknown. OBJECTIVE The aim was to determine the regulation of retinoid uptake and RA action in primary stromal cells from endometrium (n = 10) or endometriosis (n = 10). RESULTS Progesterone receptor was necessary for high STRA6 and CRABP2 expression in endometrial stromal cells. STRA6, which was responsible for labeled retinoid uptake, was strikingly lower in endometriotic cells compared to endometrial cells. CRABP2 knockdown in endometrial cells increased survival, and FABP5 knockdown in endometriotic cells decreased survival without altering the expression of downstream nuclear retinoic acid receptor α and peroxisome-proliferator-activated receptor β/δ. CONCLUSIONS In endometrial stromal cells, progesterone receptor up-regulates expression of STRA6 and CRABP2, which control retinol uptake and growth-suppressor actions of RA. In endometriotic stromal cells, decreased expression of these genes leads to decreased retinol uptake and dominant FABP5-mediated prosurvival activity.
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Affiliation(s)
- Mary Ellen Pavone
- Division of Reproductive Biology Research, Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University, Chicago, Illinois 60611, USA
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