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Wortmann SB, Chen MA, Colombo R, Pontoglio A, Alhaddad B, Botto LD, Yuzyuk T, Coughlin CR, Descartes M, Grűnewald S, Maranda B, Mills PB, Pitt J, Potente C, Rodenburg R, Kluijtmans LAJ, Sampath S, Pai EF, Wevers RA, Tiller GE. Mild orotic aciduria in UMPS heterozygotes: a metabolic finding without clinical consequences. J Inherit Metab Dis 2017; 40:423-431. [PMID: 28205048 PMCID: PMC5393157 DOI: 10.1007/s10545-017-0015-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/05/2017] [Accepted: 01/09/2017] [Indexed: 12/04/2022]
Abstract
BACKGROUND Elevated urinary excretion of orotic acid is associated with treatable disorders of the urea cycle and pyrimidine metabolism. Establishing the correct and timely diagnosis in a patient with orotic aciduria is key to effective treatment. Uridine monophosphate synthase is involved in de novo pyrimidine synthesis. Uridine monophosphate synthase deficiency (or hereditary orotic aciduria), due to biallelic mutations in UMPS, is a rare condition presenting with megaloblastic anemia in the first months of life. If not treated with the pyrimidine precursor uridine, neutropenia, failure to thrive, growth retardation, developmental delay, and intellectual disability may ensue. METHODS AND RESULTS We identified mild and isolated orotic aciduria in 11 unrelated individuals with diverse clinical signs and symptoms, the most common denominator being intellectual disability/developmental delay. Of note, none had blood count abnormalities, relevant hyperammonemia or altered plasma amino acid profile. All individuals were found to have heterozygous alterations in UMPS. Four of these variants were predicted to be null alleles with complete loss of function. The remaining variants were missense changes and predicted to be damaging to the normal encoded protein. Interestingly, family screening revealed heterozygous UMPS variants in combination with mild orotic aciduria in 19 clinically asymptomatic family members. CONCLUSIONS We therefore conclude that heterozygous UMPS-mutations can lead to mild and isolated orotic aciduria without clinical consequence. Partial UMPS-deficiency should be included in the differential diagnosis of mild orotic aciduria. The discovery of heterozygotes manifesting clinical symptoms such as hypotonia and developmental delay are likely due to ascertainment bias.
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Affiliation(s)
- Saskia B Wortmann
- Department of Pediatrics, Salzburger Landeskliniken (SALK) and Paracelsus Medical University (PMU), Mullner Hauptstrasse 48, 5020, Salzburg, Austria.
- Institute of Human Genetics, Helmholtz Zentrum Munich, Neuherberg, Germany.
- Institute of Human Genetics, Technical University Munich, Munich, Germany.
| | | | - Roberto Colombo
- Institute of Clinical Biochemistry, Faculty of Medicine, Catholic University of the Sacred Heart, Rome, Italy
| | - Alessandro Pontoglio
- Center for the Study of Rare Hereditary Diseases, Niguarda Ca' Granda Metropolitan Hospital, Milan, Italy
| | - Bader Alhaddad
- Institute of Human Genetics, Technical University Munich, Munich, Germany
| | - Lorenzo D Botto
- Department of Genetics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Tatiana Yuzyuk
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
- ARUP Laboratories, Salt Lake City, UT, USA
| | - Curtis R Coughlin
- Department of Pediatrics, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Maria Descartes
- Departments of Genetics and Pediatrics, University of Alabama School of Medicine, Birmingham, AL, USA
| | - Stephanie Grűnewald
- Metabolic Medicine Department, Great Ormond Street Hospital for Children NHS Foundation Trust, and UCL Institute of Child Health, London, UK
| | - Bruno Maranda
- CHUS Genetic Services, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Philippa B Mills
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, UK
| | - James Pitt
- Victorian Clinical Genetics Services, Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Australia
| | | | - Richard Rodenburg
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Leo A J Kluijtmans
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Emil F Pai
- Princess Margaret Cancer Centre, and Departments of Biochemistry, Medical Biophysics, and Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Ron A Wevers
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - George E Tiller
- Department of Genetics, Kaiser Permanente, Los Angeles, CA, USA
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Duley JA, Henman MG, Carpenter KH, Bamshad MJ, Marshall GA, Ooi CY, Wilcken B, Pinner JR. Elevated plasma dihydroorotate in Miller syndrome: Biochemical, diagnostic and clinical implications, and treatment with uridine. Mol Genet Metab 2016; 119:83-90. [PMID: 27370710 DOI: 10.1016/j.ymgme.2016.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 06/13/2016] [Accepted: 06/13/2016] [Indexed: 01/11/2023]
Abstract
BACKGROUND Miller syndrome (post-axial acrofacial dysostosis) arises from gene mutations for the mitochondrial enzyme dihydroorotate dehydrogenase (DHODH). Nonetheless, despite demonstrated loss of enzyme activity dihydroorotate (DHO) has not been shown to accumulate, but paradoxically urine orotate has been reported to be raised, confusing the metabolic diagnosis. METHODS We analysed plasma and urine from a 4-year-old male Miller syndrome patient. DHODH mutations were determined by PCR and Sanger sequencing. Analysis of DHO and orotic acid (OA) in urine, plasma and blood-spot cards was performed using liquid chromatography-tandem mass spectrometry. In vitro stability of DHO in distilled water and control urine was assessed for up to 60h. The patient received a 3-month trial of oral uridine for behavioural problems. RESULTS The patient had early liver complications that are atypical of Miller syndrome. DHODH genotyping demonstrated compound-heterozygosity for frameshift and missense mutations. DHO was grossly raised in urine and plasma, and was detectable in dried spots of blood and plasma. OA was raised in urine but undetectable in plasma. DHO did not spontaneously degrade to OA. Uridine therapy did not appear to resolve behavioural problems during treatment, but it lowered plasma DHO. CONCLUSION This case with grossly raised plasma DHO represents the first biochemical confirmation of functional DHODH deficiency. DHO was also easily detectable in dried plasma and blood spots. We concluded that DHO oxidation to OA must occur enzymatically during renal secretion. This case resolved the biochemical conundrum in previous reports of Miller syndrome patients, and opened the possibility of rapid biochemical screening.
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Affiliation(s)
- John A Duley
- School of Pharmacy and Mater Research Institute, The University of Queensland, Brisbane, QLD 4102, Australia.
| | - Michael G Henman
- Department of Pathology, Mater Health Services, Brisbane, QLD 4101, Australia.
| | - Kevin H Carpenter
- NSW Biochemical Genetics Service, The Children's Hospital at Westmead, Disciplines of Genetic Medicine & Child and Adolescent Health, The University of Sydney, NSW 2145, Australia.
| | - Michael J Bamshad
- Department of Pediatrics, University of Washington, Division of Genetic Medicine at Seattle Children's Hospital, Seattle, WA 98195, USA.
| | - George A Marshall
- Department of Pathology, Mater Health Services, Brisbane, QLD 4101, Australia.
| | - Chee Y Ooi
- School of Women's and Children's Health, University of NSW, Sydney Children's Hospital, Sydney, NSW 2031, Australia; School of Medicine, University of NSW, Sydney Children's Hospital, Sydney, NSW, 2031, Australia.
| | - Bridget Wilcken
- Department of Medical Genetics, Sydney Children's Hospital, University of Sydney, NSW 2031, Australia.
| | - Jason R Pinner
- Department of Medical Genomics, Royal Prince Alfred Hospital, The University of Sydney, NSW 2050, Australia.
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Villa A, Urioste M, Carrascosa MC, Vázquez S, Martínez A, Martínez-Frías ML. Pericentric inversions of chromosome 4: report of a new family and review of the literature. Clin Genet 1995; 48:255-60. [PMID: 8825604 DOI: 10.1111/j.1399-0004.1995.tb04100.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A family was cytogenetically studied because of the birth of a male child with a multiple congenital anomaly pattern, in whom a dup (4q) recombinant was found. His phenotypically normal mother's karyotype showed an apparently balanced pericentric inversion in a chromosome 4. So as to analyze the occurrence of recombinants, the cytogenetic data from this family are compared with those of the 18 previously reported familial cases of pericentric inversions (PIs) of chromosome 4. The congenital anomalies observed in the child strongly suggest Wolf-Hirschhorn syndrome but some of his clinical features seem to be pathogenetically related to the presence of lymphedema during the intrauterine period. In the multiple congenital anomaly pattern observed in this patient, the lymphedema could be the consequence of the large 4q duplication. The review of chromosome 4 PIs with 4q duplication suggests that the q3 region should be examined when edema is detected prenatally.
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Affiliation(s)
- A Villa
- ECEMC, Universidad Complutense, Madrid, Spain
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Wolf GC, Mao J, Izquierdo L, Joffe G. Paternal pericentric inversion of chromosome 4 as a cause of recurrent pregnancy loss. J Med Genet 1994; 31:153-5. [PMID: 8182725 PMCID: PMC1049681 DOI: 10.1136/jmg.31.2.153] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A paternal pericentric inversion of chromosome 4 was ascertained through karyotype analysis of an abortus specimen proven to be 46,XX,rec(4),dup q, inv (4)(p13q28). The relationship of paternal pericentric inversion to pregnancy loss is discussed, and a recommendation for karyotype analysis of recurrent abortion specimens is made.
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Affiliation(s)
- G C Wolf
- Department of Obstetrics and Gynecology, University of New Mexico School of Medicine, Albuquerque 87131
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