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Zatkova A, Ranganath L, Kadasi L. Alkaptonuria: Current Perspectives. APPLICATION OF CLINICAL GENETICS 2020; 13:37-47. [PMID: 32158253 PMCID: PMC6986890 DOI: 10.2147/tacg.s186773] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/04/2019] [Indexed: 12/13/2022]
Abstract
The last 15 years have been the most fruitful in the history of research on the metabolic disorder alkaptonuria (AKU). AKU is caused by a deficiency of homogentisate dioxygenase (HGD), the enzyme involved in metabolism of tyrosine, and is characterized by the presence of dark ochronotic pigment in the connective tissue that is formed, due to high levels of circulating homogentisic acid. Almost 120 years ago, Sir Archibald Garrod used AKU to illustrate the concept of Mendelian inheritance in man. In January 2019, the phase III clinical study SONIA 2 was completed, which tested the effectiveness and safety of nitisinone in the treatment of AKU. Results were positive, and they will serve as the basis for the application for registration of nitisinone for treatment of AKU at the European Medicines Agency. Therefore, AKU might become a rare disease for which a cure will be found by 2020. We understand the natural history of the disease and the process of ochronosis much more, but at the same time there are still unanswered questions. One of them is the issue of the factors influencing the varying severity of the disease, since our recent genotype–phenotype study did not show that differences in residual homogentisic acid activity caused by the different mutations was responsible. Although nitisinone has proved to arrest the process of ochronosis, it has some unwanted effects and does not cure the disease completely. As such, enzyme replacement or gene therapy might become a new focus of AKU research, for which a novel suitable mouse model of AKU is available already. We believe that the story of AKU is also a story of effective collaboration between scientists and patients that might serve as an example for other rare diseases.
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Affiliation(s)
- Andrea Zatkova
- Department of Human Genetics, Biomedical Research Center, Slovak Academy of Sciences, Institute of Clinical and Translational Research, Bratislava, Slovakia
| | | | - Ludevit Kadasi
- Department of Human Genetics, Biomedical Research Center, Slovak Academy of Sciences, Institute of Clinical and Translational Research, Bratislava, Slovakia.,Faculty of Natural Sciences, Department of Molecular Biology, Comenius University, Bratislava, Slovakia
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Zhou GL, Cao Y, Li M, Zhang LC, Yu YS, Jin HG. Meat quality and carcass traits in relation to HGD-BstXI and HGD-HaeIII PCR-RFLP polymorphism in Chinese red cattle. Meat Sci 2010; 85:270-3. [PMID: 20374897 DOI: 10.1016/j.meatsci.2010.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2009] [Revised: 11/06/2009] [Accepted: 01/10/2010] [Indexed: 11/15/2022]
Abstract
We investigated the effect of homogentisate 1, 2 dioxygenase (HGD) gene on meat quality and carcass traits in 287 Chinese red cattle. The PCR-SSCP method was used to identify polymorphism of the HGD gene in the exon 1 and intron 1. Two polymorphisms were detected in intron 1 and two restriction sites for endonuclease HGD-BstXI and HGD-HaeIII have also been found. The HGD-BstXI genotypes showed significant effects on cooking loss, drip loss, net meat weight, carcass weight, and eye muscle area (P<0.05). The HGD-HaeIII genotypes significant affected cooking loss, muscle fibre diameter, shear force, drip loss, and carcass yield ratio (P<0.05). Moreover, we found significant effects of diplotypes on cooking loss, muscle fibre diameter, shear force, drip loss, net meat weight, carcass weight, and eye muscle area (P<0.05).
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Affiliation(s)
- G L Zhou
- College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, People's Republic of China; College of Life Science, Liaocheng University, Liaocheng 252059, People's Republic of China
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Scriver CR. Garrod's Croonian Lectures (1908) and the charter 'Inborn Errors of Metabolism': albinism, alkaptonuria, cystinuria, and pentosuria at age 100 in 2008. J Inherit Metab Dis 2008; 31:580-98. [PMID: 18850300 DOI: 10.1007/s10545-008-0984-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 07/15/2008] [Accepted: 07/16/2008] [Indexed: 01/21/2023]
Abstract
Garrod presented his concept of 'the inborn error of metabolism' in the 1908 Croonian Lectures to the Royal College of Physicians (London); he used albinism, alkaptonuria, cystinuria and pentosuria to illustrate. His lectures are perceived today as landmarks in the history of biochemistry, genetics and medicine. Garrod gave evidence for the dynamic nature of metabolism by showing involvement of normal metabolites in normal pathways made variant by Mendelian inheritance. His concepts and evidence were salient primarily among biochemists, controversial among geneticists because biometricians were dominant over Mendelists, and least salient among physicians who were not attracted to rare hereditary 'traits'. In 2008, at the centennial of Garrod's Croonian Lectures, each charter inborn error of metabolism has acquired its own genomic locus, a cloned gene, a repertoire of annotated phenotype-modifying alleles, a gene product with known structure and function, and altered function in the Mendelian variant.
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Abstract
Archibald Edward Garrod introduced a paradigm, new for its day, in medicine: Biochemistry is dynamic and different from the static nature of organic chemistry. It led him to think about metabolic pathways and to recognize that variation in Mendelian heredity could explain an 'inborn error of metabolism'. At the time, Garrod had no idea about the nature of a gene. Genes are now well understood, genomes are being described for one organism after another (including H. sapiens) and it is understood that genomes 'speak biochemistry (not phenotype)'. Accordingly, in the era of genomics, biochemistry and physiology become the bases of functional genomics and it is possible to appreciate why 'nothing in biology makes sense without evolution' (and nothing in medicine will make sense without biology). Mendelian, biochemical and molecular genetics together have revealed what lies behind the four canonical inborn errors described by Garrod (albinism, alkaptonuria, cystinuria and pentosuria). Both older and newer ideas in genetics, new tools for applying them, and renewed respect for the clinician-scientist will enhance our understanding of the human biological variation that accounts for variant states of health and overt disease; an 'unsimple' phenotype (phenylketonuria) is used to illustrate in some detail. What can be known and what ought to be done with knowledge about human genetics to benefit individuals, families and communities (society) is both opportunity and challenge.
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Affiliation(s)
- C R Scriver
- Department of Human Genetics, McGill University and McGill University Health Centre, Montreal, Quebec, Canada.
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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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Manning K, Al-Dhalimy M, Finegold M, Grompe M. In vivo suppressor mutations correct a murine model of hereditary tyrosinemia type I. Proc Natl Acad Sci U S A 1999; 96:11928-33. [PMID: 10518553 PMCID: PMC18389 DOI: 10.1073/pnas.96.21.11928] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hereditary tyrosinemia type I and alkaptonuria are disorders of tyrosine catabolism caused by deficiency of fumarylacetoacetate hydrolase (FAH) and homogentisic acid dioxygenase (HGD), respectively. Tyrosinemia is a severe childhood disease that affects the liver and kidneys, but alkaptonuria is a more benign adult disorder in comparison. Because HGD is upstream of FAH in the tyrosine pathway, mice doubly mutant in both enzymes were found to be protected from the liver and renal damage of tyrosinemia as hypothesized. Mice mutant at the tyrosinemic locus but heterozygous for alkaptonuria spontaneously developed clonal nodules of functionally normal hepatocytes that were able to rescue the livers of some mice with this genotype. This phenotypic rescue was a result of an inactivating mutation of the wild-type homogentisic acid dioxygenase gene, thus presenting an example of an in vivo suppressor mutation in a mammalian model.
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Affiliation(s)
- K Manning
- Department of Molecular and Medical Genetics, Oregon Health Sciences University, Portland, OR 97201, USA.
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Felbor U, Mutsch Y, Grehn F, Müller CR, Kress W. Ocular ochronosis in alkaptonuria patients carrying mutations in the homogentisate 1,2-dioxygenase gene. Br J Ophthalmol 1999; 83:680-3. [PMID: 10340975 PMCID: PMC1723057 DOI: 10.1136/bjo.83.6.680] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To assess the involvement of the recently identified human homogentisate 1,2-dioxygenase gene (HGO) in alkaptonuria (AKU) in two unrelated patients with ochronosis of the conjunctiva, sclera, and cornea. METHODS A mutation screen of the entire coding region of the HGO gene was performed using single stranded conformational analysis after polymerase chain reaction with oligonucleotide primers flanking all 14 exons of the HGO gene. Fragments showing aberrant mobility were directly sequenced. RESULTS Two homozygous missense mutations, L25P and M368V, were identified, each of which leads to the replacement of a highly conserved amino acid in the HGO protein. CONCLUSIONS The authors describe a novel mutation, L25P, in the German population and bring to 18 the total number of known HGO mutations.
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Affiliation(s)
- U Felbor
- Augenklinik, Universität Würzburg, Würzburg, Germany
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Beltrán-Valero de Bernabé D, Granadino B, Chiarelli I, Porfirio B, Mayatepek E, Aquaron R, Moore MM, Festen JJ, Sanmartí R, Peñalva MA, de Córdoba SR. Mutation and polymorphism analysis of the human homogentisate 1, 2-dioxygenase gene in alkaptonuria patients. Am J Hum Genet 1998; 62:776-84. [PMID: 9529363 PMCID: PMC1377044 DOI: 10.1086/301805] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Alkaptonuria (AKU), a rare hereditary disorder of phenylalanine and tyrosine catabolism, was the first disease to be interpreted as an inborn error of metabolism. AKU patients are deficient for homogentisate 1,2 dioxygenase (HGO); this deficiency causes homogentisic aciduria, ochronosis, and arthritis. We cloned the human HGO gene and characterized two loss-of-function mutations, P230S and V300G, in the HGO gene in AKU patients. Here we report haplotype and mutational analysis of the HGO gene in 29 novel AKU chromosomes. We identified 12 novel mutations: 8 (E42A, W97G, D153G, S189I, I216T, R225H, F227S, and M368V) missense mutations that result in amino acid substitutions at positions conserved in HGO in different species, 1 (F10fs) frameshift mutation, 2 intronic mutations (IVS9-56G-->A, IVS9-17G-->A), and 1 splice-site mutation (IVS5+1G-->T). We also report characterization of five polymorphic sites in HGO and describe the haplotypic associations of alleles at these sites in normal and AKU chromosomes. One of these sites, HGO-3, is a variable dinucleotide repeat; IVS2+35T/A, IVS5+25T/C, and IVS6+46C/A are intronic sites at which single nucleotide substitutions (dimorphisms) have been detected; and c407T/A is a relatively frequent nucleotide substitution in the coding sequence, exon 4, resulting in an amino acid change (H80Q). These data provide insight into the origin and evolution of the various AKU alleles.
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