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Vöcking O, Famulski JK. A temporal single cell transcriptome atlas of zebrafish anterior segment development. Sci Rep 2023; 13:5656. [PMID: 37024546 PMCID: PMC10079958 DOI: 10.1038/s41598-023-32212-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 03/24/2023] [Indexed: 04/08/2023] Open
Abstract
Anterior segment dysgenesis (ASD), resulting in vision impairment, stems from maldevelopment of anterior segment (AS) tissues. Incidence of ASD has been linked to malfunction of periocular mesenchyme cells (POM). POM cells specify into anterior segment mesenchyme (ASM) cells which colonize and produce AS tissues. In this study we uncover ASM developmental trajectories associated with formation of the AS. Using a transgenic line of zebrafish that fluorescently labels the ASM throughout development, Tg[foxc1b:GFP], we isolated GFP+ ASM cells at several developmental timepoints (48-144 hpf) and performed single cell RNA sequencing. Clustering analysis indicates subdifferentiation of ASM as early as 48 hpf and subsequent diversification into corneal epithelium/endothelium/stroma, or annular ligament (AL) lineages. Tracking individual clusters reveals common developmental pathways, up to 72 hpf, for the AL and corneal endothelium/stroma and distinct pathways for corneal epithelium starting at 48 hpf. Spatiotemporal validation of over 80 genes found associated with AS development demonstrates a high degree of conservation with mammalian trabecular meshwork and corneal tissues. In addition, we characterize thirteen novel genes associated with annular ligament and seven with corneal development. Overall, the data provide a molecular verification of the long-standing hypothesis that POM derived ASM give rise to AS tissues and highlight the high degree of conservation between zebrafish and mammals.
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Affiliation(s)
- Oliver Vöcking
- Department of Biology, University of Kentucky, Lexington, USA
| | - J K Famulski
- Department of Biology, University of Kentucky, Lexington, USA.
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Abstract
PURPOSE To report a case of alkaptonuria (AKU) in a patient with bilateral conjunctival and scleral black colorization who was diagnosed with glaucoma thereafter. METHODS This is a single case report. RESULTS A 67-year-old male patient with bilateral black colorization of conjunctiva and sclera was referred to our hospital. In the biomicroscopic examination, globular dark pigmentation was observed in the conjunctiva, sclera, and limbal cornea. The patient was diagnosed with a nuclear cataract in both eyes. He also had gray skin pigmentation at his nose and paranasal area. Corneal topography examination revealed irregular astigmatism. Intraocular pressure values were 29 and 31 mm Hg, in the right and left eye, respectively, with Goldmann applanation tonometry. The diagnosis of AKU was made after pathologic assessment of conjunctival biopsy by the internal medicine department. CONCLUSIONS AKU is characterized by the accumulation of homogentisic acid in the connective tissues of many organs including the eye. Patients should be carefully examined in ophthalmology clinics in order to not miss systemic diagnoses. It should be kept in mind that AKU may cause iridocorneal angle pigmentation, which leads to glaucoma, and patients should be treated with proper medication when presenting with elevated intraocular pressure values.
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Abstract
Alkaptonuria is a rare inborn error of metabolism with autosomal recessive inheritance with a mutation in homogentisate 1,2-dioxygenase. It results in accumulation of homogentisic acid in connective tissues (ochronosis). Most common ocular manifestations are bluish-black discoloration of the conjunctiva, cornea, and sclera. In this case report, a 39-year-old Indian male patient with additional ocular features in the retina is described.
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Affiliation(s)
- Nirupama Damarla
- Department of Ophthalmology, Apollo Institute of Medical Sciences and Research, Jubilee Hills, Hyderabad, Telangana, India
| | - Prathima Linga
- Department of Ophthalmology, Apollo Institute of Medical Sciences and Research, Jubilee Hills, Hyderabad, Telangana, India
| | - Mallika Goyal
- Department of Ophthalmology, Apollo Institute of Medical Sciences and Research, Jubilee Hills, Hyderabad, Telangana, India
| | - Sanjay Reddy Tadisina
- Department of Ophthalmology, Apollo Institute of Medical Sciences and Research, Jubilee Hills, Hyderabad, Telangana, India
| | - G Satyanarayana Reddy
- Department of Ophthalmology, Apollo Institute of Medical Sciences and Research, Jubilee Hills, Hyderabad, Telangana, India
| | - Hymavathi Bommisetti
- Department of Ophthalmology, Apollo Institute of Medical Sciences and Research, Jubilee Hills, Hyderabad, Telangana, India
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Taşkıran E, Yaşar Taş M, Hışmi B, Demet İnce F, Ekmekçi S, Solakoğlu Kahraman D, Akar H. A late diagnosis of alkaptonuria in an elderly patient. Eur Geriatr Med 2017. [DOI: 10.1016/j.eurger.2016.12.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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In Vivo Confocal Microscopy and Anterior Segment Optic Coherence Tomography Findings in Ocular Ochronosis. Case Rep Ophthalmol Med 2016; 2015:592847. [PMID: 26788390 PMCID: PMC4693010 DOI: 10.1155/2015/592847] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 11/20/2015] [Accepted: 11/23/2015] [Indexed: 11/17/2022] Open
Abstract
Purpose. To report clinical and in vivo confocal microscopy (IVCM) findings of two patients with ocular ochronosis secondary due to alkaptonuria. Materials and Methods. Complete ophthalmologic examinations, including IVCM (HRT II/Rostock Cornea Module, Heidelberg, Germany), anterior segment optical coherence tomography (AS-OCT) (Topcon 3D spectral-domain OCT 2000, Topcon Medical Systems, Paramus, NJ, USA), corneal topography (Pentacam, OCULUS Optikgeräte GmbH, Wetzlar, Germany), and anterior segment photography, were performed. Results. Biomicroscopic examination showed bilateral darkly pigmented lesions of the nasal and temporal conjunctiva and episclera in both patients. In vivo confocal microscopy of the lesions revealed prominent degenerative changes, including vacuoles and fragmentation of collagen fibers in the affected conjunctival lamina propria and episclera. Hyperreflective pigment granules in different shapes were demonstrated in the substantia propria beneath the basement membrane. AS-OCT of Case 1 demonstrated hyporeflective areas. Fundus examination was within normal limits in both patients, except tilted optic discs with peripapillary atrophy in one of the patients. Corneal topography, thickness, and macular OCT were normal bilaterally in both cases. Conclusion. The degenerative and anatomic changes due to ochronotic pigment deposition in alkaptonuria can be demonstrated in detail with IVCM and AS-OCT. Confocal microscopic analysis in ocular ochronosis may serve as a useful adjunct in diagnosis and monitoring of the disease progression.
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Braconi D, Millucci L, Ghezzi L, Santucci A. Redox proteomics gives insights into the role of oxidative stress in alkaptonuria. Expert Rev Proteomics 2014; 10:521-35. [PMID: 24206226 DOI: 10.1586/14789450.2013.858020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Alkaptonuria (AKU) is an ultra-rare metabolic disorder of the catabolic pathway of tyrosine and phenylalanine that has been poorly characterized at molecular level. As a genetic disease, AKU is present at birth, but its most severe manifestations are delayed due to the deposition of a dark-brown pigment (ochronosis) in connective tissues. The reasons for such a delayed manifestation have not been clarified yet, though several lines of evidence suggest that the metabolite accumulated in AKU sufferers (homogentisic acid) is prone to auto-oxidation and induction of oxidative stress. The clarification of the pathophysiological molecular mechanisms of AKU would allow a better understanding of the disease, help find a cure for AKU and provide a model for more common rheumatic diseases. With this aim, we have shown how proteomics and redox proteomics might successfully overcome the difficulties of studying a rare disease such as AKU and the limitations of the hitherto adopted approaches.
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Affiliation(s)
- Daniela Braconi
- Dipartimento di Biotecnologie, Chimica e Farmacia, via Fiorentina 1, Università degli Studi di Siena, 53100 Siena, Italy
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Lindner M, Bertelmann T. On the ocular findings in ochronosis: a systematic review of literature. BMC Ophthalmol 2014; 14:12. [PMID: 24479547 PMCID: PMC3915032 DOI: 10.1186/1471-2415-14-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 01/27/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ochronosis/Alkaptonuria is a tyrosine metabolism disorder where accumulation of homogentisic acid, in eye, skin, cartilage and several other connective tissues leads to a black pigmentation of the affected tissues. It is autosomal-recessive inherited in men with a frequency of 1-9/1,000,000. While it is clear that pigment deposits lead to joint destruction, renal stone formation and cardiac valvulopathy respectively, the significance of ocular findings is still unclear. We therefore aim to evaluate the frequency and clinical significance of ocular findings in ochronosis and discuss possible therapeutic options. METHODS Systematic review of literature via Medline and Web of Science. Only case reports in English, German, French, Spanish or Italian documenting detailed ophthalmologic examination were included. RESULTS Our search revealed 36 case reports including 40 patients. Average age at the onset of ocular signs was 40.6 years. The most frequent sign was symmetric brown sclera pigmentation present in 82.5 percent of the patients. "Oil-drops", brown pigment spots in the limbus are generally considered pathognomonic but were a little less frequent (75 percent). Vermiform pigment deposits at the level of the conjunctiva or increased conjunctival vessel diameter is also frequent. We found an increased incidence of central vein occlusion and elevated intraocular pressure going along with chamber angle hyperpigmentation. Another condition observed twice is rapid progressive astigmatism attributable to corneoscleral pigment accumulation. CONCLUSION Our observations suggest that ocular findings are of double relevance. First, characteristic ocular findings can anticipate the time of diagnosis and second, ocular findings may complicate to various conditions putting sight at risk. Opthalmologists and general physicians should be aware of both. Therapeutic options include protein restriction, administration of high dose vitamin C or nitisonone. Evidence for all of them is limited.
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Affiliation(s)
- Moritz Lindner
- Department of Ophthalmology, University of Bonn, Ernst-Abbe-Street 2, Bonn 53127, Germany
| | - Thomas Bertelmann
- Department of Ophthalmology, Philipps University Marburg, Baldinger-Street, Marburg 35043, Germany
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Conway RE, Joiner K, Patterson A, Bourgeois D, Rampp R, Hannah BC, McReynolds S, Elder JM, Gilfilen H, Shapiro LH. Prostate specific membrane antigen produces pro-angiogenic laminin peptides downstream of matrix metalloprotease-2. Angiogenesis 2013; 16:847-60. [PMID: 23775497 DOI: 10.1007/s10456-013-9360-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 06/10/2013] [Indexed: 12/18/2022]
Abstract
Prostate specific membrane antigen (PSMA) is a pro-angiogenic cell-surface protease that we previously demonstrated regulates blood vessel formation in a laminin and integrin β1-dependent manner. Here, we examine the principal mechanism of PSMA activation of integrin β1. We show that digesting laminin sequentially with recombinant matrix metalloprotease-2 (MMP-2) and PSMA generates small peptides that enhance endothelial cell adhesion and migration in vitro. We also provide evidence that these laminin peptides activate adhesion via integrin α6β1 and focal adhesion kinase. Using an in vivo Matrigel implant assay, we show that these MMP/PSMA-derived laminin peptides also increase angiogenesis in vivo. Together, our results reveal a novel mechanism of PSMA activation of angiogenesis by processing laminin downstream of MMP-2.
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Affiliation(s)
- Rebecca E Conway
- Department of Biology, College of Arts and Sciences, Lipscomb University, Nashville, TN, 37204, USA,
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Zatkova A. An update on molecular genetics of Alkaptonuria (AKU). J Inherit Metab Dis 2011; 34:1127-36. [PMID: 21720873 DOI: 10.1007/s10545-011-9363-z] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 06/01/2011] [Accepted: 06/08/2011] [Indexed: 11/25/2022]
Abstract
Alkaptonuria (AKU) is an autosomal recessive disorder caused by a deficiency of homogentisate 1,2 dioxygenase (HGD) and characterized by homogentisic aciduria, ochronosis, and ochronotic arthritis. The defect is caused by mutations in the HGD gene, which maps to the human chromosome 3q21-q23. AKU shows a very low prevalence (1:100,000-250,000) in most ethnic groups, but there are countries such as Slovakia and the Dominican Republic in which the incidence of this disorder rises to as much as 1:19,000. In this work, we summarize the genetic aspects of AKU in general and the distribution of all known disease-causing mutations reported so far. We focus on special features of AKU in Slovakia, which is one of the countries with an increased incidence of this rare metabolic disorder.
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Affiliation(s)
- Andrea Zatkova
- Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlarska 5, 833 34, Bratislava, Slovakia.
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Abstract
In a 69-year-old man with ochronosis, circumscribed brown-black scleral spots with injection of conjunctival vessels and some small pigmentations of the peripheral superficial cornea occurred. Ochronosis is an autosomal recessive chronic disease, whereby early detection of cardiac valvular defects and arthritis is important particularly in patients who are older than 40 years.
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Khaled A, Kerkeni N, Hawilo A, Fazaa B, Kamoun MR. Endogenous ochronosis: case report and a systematic review of the literature. Int J Dermatol 2011; 50:262-7. [PMID: 21342157 DOI: 10.1111/j.1365-4632.2010.04668.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Endogenous ochronosis (EO) is a rare autosomal recessive disorder due to accumulation of oxidized and polymerized forms of homogentisic acid (HGA) in connective tissues, giving them a deep dark blue pigmentation. AIM Through a new Tunisian case of EO and a review of the literature, we aimed to define the epidemioclinical features of EO, its diagnostic criteria, and evolution. METHODS Three hundred and forty patients were enrolled through 54 articles and four abstracts. CASE REPORT A 35-year-old woman, born in consanguineous parents, presented with blue-grey patches of fingernails, first interdigital spaces, and ears with brown conjunctival pigmentation. Urine specimen turned dark on standing overnight. The diagnosis of EO was confirmed by urinary high levels of HGA. Investigations revealed radiologic signs of ochronotic arthropathy. REVIEW OF THE LITERATURE EO is ubiquitary. Its prevalence was estimated at almost 6.5 cases/year. The mean age at diagnosis was 55.9 years (M/F: 1.85). Onset symptoms mainly consisted in cutaneous signs. Ochronotic arthropathy was the most frequently reported manifestation. Treatment was mainly symptomatic. DISCUSSION EO is often revealed in adulthood mainly after the fourth decade. Urinary darkening is the first sign of the disease but is rarely reported as an onset sign. Skin signs are the alerting features. Ochronotic arthropathy is insidious but may be debilitating. No specific medical treatment of EO is available. CONCLUSION Cutaneous manifestations are the hallmarks of OE. As vital organ involvement has been reported, close monitoring and continuous surveillance is warranted.
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Affiliation(s)
- Aida Khaled
- Department of Dermatology, Charles Nicolle Hospital, Tunis, Tunisia.
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A late and difficult diagnosis of ochronosis. J Med Life 2010; 3:437-43. [PMID: 21254745 PMCID: PMC3019075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alkaptonuria is a rare autosomal recessive disorder of metabolism caused by deficiency of homogentisic acid oxidase and resulting in accumulation of homogentisic acid in collagenous structures. This causes the classic clinical triad: (1) homogentisic aciduria (urine blackens on standing when oxidized or alkalinized); (2) eumelanin-like pigmentation of skin, sclera, cartilages, etc and (3) degenerative ochronic arthropathies usually in the fourth decade of life. Other important but more rare consequences of alkaptonuric ochronosis are cardiovascular and urinary tract involvement. We present a case of ochronosis with multiple visceral involvement: skin (fingers, ear sclera), severe spondylarthropaty with extensive calcifications of intervertebral discs and reduced mobility, osteoarthritis of both knees, right hip ostonecrosis, cardiovascular involvement (severe stenosis and insufficiency of aortic valve that) and urinary tract involvement (nephrolitiasis)
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Vilboux T, Kayser M, Introne W, Suwannarat P, Bernardini I, Fischer R, O'Brien K, Kleta R, Huizing M, Gahl WA. Mutation spectrum of homogentisic acid oxidase (HGD) in alkaptonuria. Hum Mutat 2010; 30:1611-9. [PMID: 19862842 DOI: 10.1002/humu.21120] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Alkaptonuria (AKU) is a rare autosomal recessive metabolic disorder, characterized by accumulation of homogentisic acid, leading to darkened urine, pigmentation of connective tissue (ochronosis), joint and spine arthritis, and destruction of cardiac valves. AKU is due to mutations in the homogentisate dioxygenase gene (HGD) that converts homogentisic acid to maleylacetoacetic acid in the tyrosine catabolic pathway. Here we report a comprehensive mutation analysis of 93 patients enrolled in our study, as well as an extensive update of all previously published HGD mutations associated with AKU. Within our patient cohort, we identified 52 HGD variants, of which 22 were novel. This yields a total of 91 identified HGD variations associated with AKU to date, including 62 missense, 13 splice site, 10 frameshift, 5 nonsense, and 1 no-stop mutation. Most HGD variants reside in exons 3, 6, 8, and 13. We assessed the potential effect of all missense variations on protein function, using five bioinformatic tools specifically designed for interpretation of missense variants (SIFT, POLYPHEN, PANTHER, PMUT, and SNAP). We also analyzed the potential effect of splice-site variants using two different tools (BDGP and NetGene2). This study provides valuable resources for molecular analysis of alkaptonuria and expands our knowledge of the molecular basis of this disease.
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Affiliation(s)
- Thierry Vilboux
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health (NIH), Bethesda, Maryland 20892, USA.
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Ben Rayana N, Chahed N, Khochtali S, Ghorbel M, Hamdi R, Rouis M, Bouajina I, Ben Hadj Hamida F. Manifestations oculaires de l’ochronose. J Fr Ophtalmol 2008. [DOI: 10.1016/s0181-5512(08)75467-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ladjouze-Rezig A, Rodriguez de Cordoba S, Aquaron R. Le rhumatisme alcaptonurique en Algérie : étude clinique, radiologique, biologique et moléculaire : à propos de 14 cas dans 11 familles. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.rhum.2005.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ladjouze-Rezig A, Rodriguez de Cordoba S, Aquaron R. Ochronotic rheumatism in Algeria: clinical, radiological, biological and molecular studies—a case study of 14 patients in 11 families. Joint Bone Spine 2006; 73:284-92. [PMID: 16085442 DOI: 10.1016/j.jbspin.2005.03.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Accepted: 03/30/2005] [Indexed: 11/22/2022]
Abstract
OBJECTIVES To confirm alkaptonuria and ochronotic arthropathy diagnosis by mutation screening of the homogentisate 1,2-dioxygenase (HGD) gene. Try to establish a genotype-phenotype correlation in the five subjects with a molecular study on HGD gene. METHODS We report 14 alkaptonuria cases (10 men and four women) in 11 Algerian families. Consanguineous matings were evidenced in only three families (F = 1/16). Molecular analysis was performed by sequencing genomic DNA in order to identify the mutations of the HGD gene. RESULTS Alkaptonuria was always confirmed by urinary homogentisic acid determination. Four different mutations of the HGD gene were found: an homozygous missense mutation, Serine189Isoleucine in two sisters with a mild phenotype; an homozygous splice site mutation (IVS1-1G > A) in a man with a severe phenotype (death at 61 years old from renal failure); a silent mutation, Alanine470Alanine at the heterozygous state in a man with a mild phenotype; a 'G' deletion at the position c.819 which causes a frameshift after Gly217(Gly217fs) that runs into a stop codon at c. 850. This mutation is novel and was found in heterozygosis in a woman with a mild phenotype. CONCLUSIONS The two homozygous mutations were associated, respectively, with a severe and a mild phenotype but no genotype-phenotype correlation could be found.
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Bacchetti S, Zeppieri M, Brusini P. A case of ocular ochronosis and chronic open-angle glaucoma: merely coincidental? ACTA ACUST UNITED AC 2004; 82:631-2. [PMID: 15453872 DOI: 10.1111/j.1600-0420.2004.00288.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Zatkova A, Chmelikova A, Polakova H, Ferakova E, Kadasi L. Rapid detection methods for five HGO gene mutations causing alkaptonuria. Clin Genet 2003; 63:145-9. [PMID: 12630963 DOI: 10.1034/j.1399-0004.2003.00027.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Alkaptonuria (AKU) is an autosomal recessive disorder caused by the deficiency of homogentisate 1,2 dioxygenase (HGO) activity. The disease is characterized by homogentisic aciduria, ochronosis and ochronotic arthritis. AKU shows a very low prevalence (1:250 000), in most ethnic groups. Altogether 43 HGO mutations have been identified in approximately 100 patients. In Slovakia, however, the incidence of this disorder rises up to 1:19 000, and 10 different AKU mutations have been identified in this relatively small country. Here, we report detection methods developed for rapid identification of five HGO mutations. PCR primers were designed enabling detection of mutations IVS5 + 1G-->A, R58fs, and V300G by restriction digestion of amplification-created restriction sites (ACRS). Mutation G152fs is readily identified by heteroduplex analysis, and G161R by amplification refractory mutation system (ARMS) PCR.
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Affiliation(s)
- A Zatkova
- Institute of Molecular Physiology and Genetics, Faculty of Natural Sciences, Comenius University Bratislava, Bratislava, Slovakia
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Söker Cakmak S, Cevik R, Aksünger A, Unlü K, Ava S. Ocular ochronosis: A case report and clinical findings. ACTA OPHTHALMOLOGICA SCANDINAVICA 2002; 80:340-2. [PMID: 12059878 DOI: 10.1034/j.1600-0420.2002.800321.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE To report a rare case of bilateral asymmetrical melanin-like pigments found in the cornea, conjunctiva and sclera. METHODS Systemic investigation with clinical and laboratory analysis. RESULTS The case was diagnosed as one of alkaptonuria and ocular ochronosis.
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Affiliation(s)
- Sevin Söker Cakmak
- Department of Ophthalmology, University of Dicle, School of Medicine, Diyarbakir, Turkey.
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Zatková A, de Bernabé DB, Poláková H, Zvarík M, Feráková E, Bosák V, Ferák V, Kádasi L, de Córdoba SR. High frequency of alkaptonuria in Slovakia: evidence for the appearance of multiple mutations in HGO involving different mutational hot spots. Am J Hum Genet 2000; 67:1333-9. [PMID: 11017803 PMCID: PMC1288576 DOI: 10.1016/s0002-9297(07)62964-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2000] [Accepted: 09/13/2000] [Indexed: 11/20/2022] Open
Abstract
Alkaptonuria (AKU) is an autosomal recessive disorder caused by the deficiency of homogentisate 1,2 dioxygenase (HGO) activity. AKU shows a very low prevalence (1:100,000-250,000) in most ethnic groups. One notable exception is in Slovakia, where the incidence of AKU rises to 1:19,000. This high incidence is difficult to explain by a classical founder effect, because as many as 10 different AKU mutations have been identified in this relatively small country. We have determined the allelic associations of 11 HGO intragenic polymorphisms for 44 AKU chromosomes from 20 Slovak pedigrees. These data were compared to the HGO haplotype data available in our laboratory for >80 AKU chromosomes from different European and non-European countries. The results show that common European AKU chromosomes have had only a marginal contribution to the Slovak AKU gene pool. Six of the ten Slovak AKU mutations, including the prevalent G152fs, G161R, G270R, and P370fs mutations, most likely originated in Slovakia. Data available for 17 Slovak AKU pedigrees indicate that most of the AKU chromosomes have their origins in a single very small region in the Carpathian mountains, in the northwestern part of the country. Since all six Slovak AKU mutations are associated with HGO mutational hot spots, we suggest that an increased mutation rate at the HGO gene is responsible for the clustering of AKU mutations in such a small geographical region.
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Affiliation(s)
- A Zatková
- Institute of Molecular Physiology and Genetics, Comenius University Bratislava, Bratislava
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Zatkova A, de Bernabe DBV, Polakova H, Zvarik M, Ferakova E, Bošak V, Ferak V, Kadasi L, de Cordoba SR. High Frequency of Alkaptonuria in Slovakia: Evidence for the Appearance of Multiple Mutations inHGOInvolving Different Mutational Hot Spots. Am J Hum Genet 2000. [DOI: 10.1086/321209] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Rodríguez JM, Timm DE, Titus GP, Beltrán-Valero De Bernabé D, Criado O, Mueller HA, Rodríguez De Córdoba S, Peñalva MA. Structural and functional analysis of mutations in alkaptonuria. Hum Mol Genet 2000; 9:2341-50. [PMID: 11001939 DOI: 10.1093/oxfordjournals.hmg.a018927] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Alkaptonuria (AKU), the prototypic inborn error of metabolism, was the first human disease to be interpreted as a Mendelian trait by Garrod and Bateson at the beginning of last century. AKU results from impaired function of homogentisate dioxygenase (HGO), an enzyme required for the catabolism of phenylalanine and tyrosine. With the novel 7 AKU and 22 fungal mutations reported here, a total of 84 mutations impairing this enzyme have been found in the HGO gene from humans and model organisms. Forty-three of these mutations result in single amino acid substitutions. This mutational information is analysed here in the context of the HGO structure and function using kinetic assays performed using purified AKU mutant enzymes and the crystal structure of human HGO. HGO is a topologically complex structure which assembles as a functional hexamer arranged as a dimer of trimers. We show how the intricate pattern of intra- and inter-subunit interactions and the extensive surfaces required for subunit folding and association of this oligomeric enzyme can be inactivated at multiple levels by single-residue substitutions. This explains, in part, the predominance of missense mutations (67%) in AKU.
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Affiliation(s)
- J M Rodríguez
- Centro de Investigaciones Biológicas CSIC, Velázquez 144, Madrid 28006, Spain
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Bálint G, Szebenyi B. Hereditary disorders mimicking and/or causing premature osteoarthritis. Best Pract Res Clin Rheumatol 2000; 14:219-50. [PMID: 10925743 DOI: 10.1053/berh.2000.0063] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Osteoarthritis is the most common joint disease, causing considerable disability and impairment of quality of life. Hereditary osteochondrodysplasias and some inborn errors of metabolism may mimic or cause premature osteoarthritis. Osteochondrodysplasias usually cause joint deformities, such as coxa vara or genu varum, which can cause abnormal biomechanics. In most of these disorders, the articular cartilage is originally defective as a result of genetically determined collagen or matrix protein abnormalities, or the deposition of mucopolysaccharides. In the case of inborn errors of metabolism, the pathological process affects healthy articular structures, causing secondary osteoarthritis. In alkaptonuria, the pathological deposition of polymerized homogenistic acid causes defective changes in cartilage, articular capsule and tendons. In Wilson's disease, the premature osteoarthritis might be caused by the copper deposition. It is worth paying attention to these rare disorders, even when they are mild or incomplete, because early diagnosis can lead to prevention and effective treatment. In addition, research is discovering the specific gene defects and molecular abnormalities that are responsible for disease expression. This may in turn lead to opportunities for prenatal diagnosis; thus, genetic counselling and gene replacement therapy may be a realistic possibility in the near future.
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Affiliation(s)
- G Bálint
- National Institute of Rheumatology and Physiotherapy, Budapest, Hungary
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