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Liu Y, Chen Z, Dong H, Ding Y, He R, Kang L, Li D, Shen M, Jin Y, Zhang Y, Song J, Tian Y, Cao Y, Liang D, Yang Y. Analysis of the relationship between phenotypes and genotypes in 60 Chinese patients with propionic acidemia: a fourteen-year experience at a tertiary hospital. Orphanet J Rare Dis 2022; 17:135. [PMID: 35331292 PMCID: PMC8944130 DOI: 10.1186/s13023-022-02271-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 02/20/2022] [Indexed: 11/21/2022] Open
Abstract
Background Propionic acidemia is a severe inherited metabolic disorder, caused by the deficiency of propionyl-CoA carboxylase which encoded by the PCCA and PCCB genes. The aim of the study was to investigate the clinical features and outcomes, molecular epidemiology and phenotype-genotype relationship in Chinese population. Methods We conducted a retrospective study of 60 Chinese patients diagnosed at Peking University First Hospital from 2007 to 2020. Their clinical and laboratory data were reviewed. The next-generation sequencing was conducted on blood samples from 58 patients. Results Only 5 (8.3%) patients were identified by newborn screening. In the rest 55 patients, 25 had early-onset (≤ 3 months) disease and 30 had late-onset (> 3 months) disease. Neurological abnormalities were the most frequent complications. Five cases detected by newborn screening had basically normal development. Nine (15%) cases died in our cohort. 24 patients (41.4%) harbored PCCA variants, and 34 (58.6%) harbored PCCB variants. 30 (11 reported and 19 novel) variants in PCCA and 28 (18 reported and 10 novel) variants in PCCB mere identified. c.2002G>A and c.937C>T in PCCA, and c.838dupC in PCCB were the most common variants in this cohort, with the frequency of 13.9% (6/44 alleles), 13.9% (6/44 alleles) and 12.5% (8/64 alleles), respectively. There was no difference in clinical features and outcomes between patients with PCCA and PCCB variants. Certain variants with high frequencies and homozygotes may be associated with early-onset or late-onset propionic acidemia. Conclusions Although the genotype–phenotype correlation is still unclear, certain variants seemed to be related to early-onset or late-onset propionic acidemia. Our study further delineated the complex clinical manifestations of propionic acidemia and expanded the spectrum of gene variants associated with propionic acidemia. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02271-3.
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Affiliation(s)
- Yi Liu
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.,Department of Clinical Laboratory, China-Japan Friendship Hospital, Beijing, 100029, China
| | - Zhehui Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Hui Dong
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Yuan Ding
- Department of Endocrinology and Genetic, Beijing Children's Hospital, Capital Medical University, Beijing, 100045, China
| | - Ruxuan He
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Lulu Kang
- Department of Pediatrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Dongxiao Li
- Department of Endocrinology and Genetic, Henan Children's Hospital, Zhengzhou, 450053, China
| | - Ming Shen
- Translational Medicine Center, Chinese PLA General Hospital, Beijing, 100853, China
| | - Ying Jin
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Yao Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Jinqing Song
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China
| | - Yaping Tian
- Translational Medicine Center, Chinese PLA General Hospital, Beijing, 100853, China
| | - Yongtong Cao
- Department of Clinical Laboratory, China-Japan Friendship Hospital, Beijing, 100029, China.
| | - Desheng Liang
- School of Life Sciences, Central South University, Changsha, 410000, China.
| | - Yanling Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.
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Propionic acidemia identified in twin siblings conceived by in vitro fertilization (IVF) with parents who were unknown carriers of a PCCA mutation. BMC Pregnancy Childbirth 2020; 20:689. [PMID: 33183246 PMCID: PMC7659086 DOI: 10.1186/s12884-020-03391-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/30/2020] [Indexed: 11/15/2022] Open
Abstract
Background Propionic acidemia (PA) is a severe monogenic disorder characterized by a deficiency of the mitochondrial protein propionyl-CoA carboxylase (PCC) enzyme, which is caused by mutations in the PCCA or PCCB gene. Preconception carrier screening could provide couples with meaningful information for their reproductive options; however, it is not widely performed in China. Case presentation This report describes a case of dizygotic twin siblings conceived by in vitro fertilization (IVF) and diagnosed with propionic acidemia (PA). Their parents had no history of PA. Tandem mass spectrometry and urine gas chromatography/mass spectrometry (GC/MS) of the twin siblings revealed markedly elevated propionyl carnitine (C3), C3/C2, and 3-hydroxypropionate in the plasma and urine. Whole-exome sequencing was performed for the twin siblings. A homozygous missense mutation, c.2002G > A (p.Gly668Arg) in PCCA, was identified in the twin siblings. Sanger sequencing confirmed the homozygous mutation in the twin siblings and identified their parents as heterozygous carriers of the c.2002G > A mutation in PCCA. Both neonates in this case died. This is an emotionally and financially devastating outcome that could have been avoided with genetic carrier screening before conception. If couples are screened before IVF and found to be silent carriers, then reproductive options (such as preimplantation genetic diagnosis or prenatal diagnosis) can be offered to achieve a healthy newborn. Conclusion This case is a reminder to infertile couples seeking IVF that it is beneficial to clarify whether they are silent carriers before undergoing IVF. Supplementary Information The online version contains supplementary material available at 10.1186/s12884-020-03391-z.
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Dai M, Xiao B, Zhang H, Ye J, Qiu W, Zhu H, Wang L, Liang L, Zhan X, Ji W, Wang Y, Yu Y, Gu X, Han L. Biochemical and genetic approaches to the prenatal diagnosis of propionic acidemia in 78 pregnancies. Orphanet J Rare Dis 2020; 15:276. [PMID: 33028371 PMCID: PMC7539428 DOI: 10.1186/s13023-020-01539-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 09/09/2020] [Indexed: 12/16/2022] Open
Abstract
Background Propionic acidemia (PA) is a serious metabolic disorder, and different approaches have been applied to its prenatal diagnosis. To evaluate the reliability and validity of a biochemical strategy in the prenatal diagnosis of PA, we conducted a retrospective study of our 11-year experiences at a single center. Methods We accumulated data from 78 pregnancies from 58 families referred to our center and provided prenatal diagnosis by directed genetic analysis and/or metabolite measurement using tandem mass spectrometry (MS/MS) and gas chromatography/mass spectrometry (GC/MS) of amniotic fluid (AF) samples. Results Sixty-five unaffected fetuses (83.33%) and 13 affected fetuses (16.67%) were confirmed in our study. The characteristic metabolites including propionylcarnitine (C3) level, C3/acetylcarnitine (C2) ratio and 2-methylcitric acid (2MCA) level in unaffected and affected groups showed significant differences (P < 0.0001), while the level of 3-hydroxypropionic acid (3HPA) showed no significant difference between the two groups (P > 0.05).Of the 78 pregnancies, 24 fetuses were found to have either one causative pathogenic variant or were without genetic information in the proband. Three of these fetuses had elevated AF levels of C3, C3/C2 ratio, and 2MCA and, thus, were determined to be affected, while the remaining fetuses were determined to be unaffected based on a normal AF metabolite profile. Our genetic and biochemical results were highly consistent with postnatal follow-up results on all unaffected fetuses. Conclusions We conclude that a biochemical approach can serve as a fast and convenient prenatal diagnostic method for pregnancies at an increased risk for PA, which could be used in conjunction with genetic testing for precise prenatal diagnosis of this disorder. In our analysis, the characteristic metabolites C3 level, C3/C2 ratio, and 2MCA level in AF supernatant were dependable biochemical markers for diagnosis, of which the C3/C2 ratio appears to be the most reliable biochemical marker for the prenatal diagnosis of PA.
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Affiliation(s)
- Mengyao Dai
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Bing Xiao
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Huiwen Zhang
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jun Ye
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wenjuan Qiu
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hong Zhu
- Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lei Wang
- Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lili Liang
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xia Zhan
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wenjun Ji
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yu Wang
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yongguo Yu
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xuefan Gu
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lianshu Han
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute of Pediatric Research, School of Medicine, Shanghai Jiao Tong University, 1665 KongJiang Road, Shanghai, 200092, China. .,Center for Prenatal Diagnosis, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
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Yang Q, Xu H, Luo J, Li M, Yi S, Zhang Q, Geng G, Feng S, Fan X. Case reports: three novel variants in PCCA and PCCB genes in Chinese patients with propionic acidemia. BMC MEDICAL GENETICS 2020; 21:72. [PMID: 32252659 PMCID: PMC7137301 DOI: 10.1186/s12881-020-01008-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 03/23/2020] [Indexed: 12/14/2022]
Abstract
Background Propionic acidemia (PA) is an autosomal recessive metabolic disorder caused by the deficiency of the mitochondrial protein propionyl-CoA carboxylase (PCC) and is associated with pathogenic variants in either of the two genes PCCA or PCCB. The present study aimed to identify the genetic cause of three Chinese patients with PA. Case presentation Three Chinese PA patients were diagnosed by using gas chromatography-mass spectrometry(GC-MS), tandem mass spectrometry (MS/MS) and molecular diagnostic methods. All patients had onset in the neonatal period. One patient died of infection and metabolic decompensation, and the other two had mild to moderate developmental delay/mental retardation. Mutation analysis of the PCCA gene identified that patient 1 carried the compound heterozygous c.1288C > T(p.R430X) and c.2002G > A(p.G668R), and patient 2 was homozygous for the c.1426C > T(p.R476X) mutation. Mutation analysis of the PCCB gene identified that patient 3 harbored the compound heterozygous mutations c.359_360del AT(p.Y120Cfs*40) and c.1398 + 1G > A. Among these mutations, three (c.1288C > T, c.359_360del AT and c.1398 + 1G > A) are novel. Conclusions We reported three Chinese PA patients who had PCCA or PCCB mutants. Among them, in the PCCA gene, c.1288C > T(p.R430X) was a nonsense mutation, resulting in a truncated protein. c.359_360del AT was a frameshift mutation, leading to a p.Y120Cfs*40 change in the amino acid sequence in the PCCB protein. c.1398 + 1G > A was a splicing mutation, causing skipping of the exons 13–14. In conclusion, the novel mutations uncovered in this study will expands the mutation spectrum of PA.
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Affiliation(s)
- Qi Yang
- Department of Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, No.59, Xiangzhu Road, Nanning, China
| | - Hong Xu
- NanNing Region Center for Disease Prevention and Control, No.55, Xiangzhu Road, Nanning, China
| | - Jingsi Luo
- Department of Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, No.59, Xiangzhu Road, Nanning, China
| | - Mengting Li
- Department of Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, No.59, Xiangzhu Road, Nanning, China
| | - Sheng Yi
- Department of Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, No.59, Xiangzhu Road, Nanning, China
| | - Qinle Zhang
- Department of Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, No.59, Xiangzhu Road, Nanning, China
| | - Guoxing Geng
- Department of Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, No.59, Xiangzhu Road, Nanning, China
| | - Shihan Feng
- Department of Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, No.59, Xiangzhu Road, Nanning, China
| | - Xin Fan
- Department of Genetic and Metabolic Central Laboratory, Guangxi Maternal and Child Health Hospital, No.59, Xiangzhu Road, Nanning, China.
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Abstract
PURPOSE OF REVIEW Recent clinical studies and management guidelines for the treatment of the organic acidopathies methylmalonic acidemia (MMA) and propionic acidemia address the scope of interventions to maximize health and quality of life. Unfortunately, these disorders continue to cause significant morbidity and mortality due to acute and chronic systemic and end-organ injury. RECENT FINDINGS Dietary management with medical foods has been a mainstay of therapy for decades, yet well controlled patients can manifest growth, development, cardiac, ophthalmological, renal, and neurological complications. Patients with organic acidopathies suffer metabolic brain injury that targets specific regions of the basal ganglia in a distinctive pattern, and these injuries may occur even with optimal management during metabolic stress. Liver transplantation has improved quality of life and metabolic stability, yet transplantation in this population does not entirely prevent brain injury or the development of optic neuropathy and cardiac disease. SUMMARY Management guidelines should identify necessary screening for patients with methylmalonic acidemia and propionic acidemia, and improve anticipatory management of progressive end-organ disease. Liver transplantation improves overall metabolic control, but injury to nonregenerative tissues may not be mitigated. Continued use of medical foods in these patients requires prospective studies to demonstrate evidence of benefit in a controlled manner.
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Cappuccio G, Atwal PS, Donti TR, Ugarte K, Merchant N, Craigen WJ, Sutton VR, Elsea SH. Expansion of the Phenotypic Spectrum of Propionic Acidemia with Isolated Elevated Propionylcarnitine. JIMD Rep 2016; 35:33-37. [PMID: 27900673 PMCID: PMC5585109 DOI: 10.1007/8904_2016_21] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 10/26/2016] [Accepted: 11/02/2016] [Indexed: 01/07/2023] Open
Abstract
We report three patients with elevations of propionylcarnitine (C3), one without elevations of 2-methylcitrate and 3-hydroxypropionate in urine organic acid analysis, and the other two showing only mild elevations, all of whom were subsequently confirmed to have propionic acidemia by molecular analysis of PCCA and PCCB genes. To date, they have had a mild clinical course. These cases illustrate the importance of considering high C3 as the only biochemical abnormality in a diagnosis of propionic acidemia. Since mild C3 elevations may be overlooked and considered non-diagnostic in isolation, we advise considering a diagnosis of propionic acidemia even in the absence of significant elevations 2-methylcitrate or 3-hydroxypropionate in urine organic acid analysis.
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Affiliation(s)
- Gerarda Cappuccio
- Department of Translational Medicine, Sector of Pediatrics, University of Naples Federico II, Naples, Italy
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Baylor Genetics Laboratories, One Baylor Plaza, Houston, TX, 77030, USA
| | - Paldeep S Atwal
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Baylor Genetics Laboratories, One Baylor Plaza, Houston, TX, 77030, USA
- Department of Clinical Genomics, Center for Individualized Medicine, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Taraka R Donti
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Baylor Genetics Laboratories, One Baylor Plaza, Houston, TX, 77030, USA
| | - Kiki Ugarte
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Nadia Merchant
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - William J Craigen
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - V Reid Sutton
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Baylor Genetics Laboratories, One Baylor Plaza, Houston, TX, 77030, USA
| | - Sarah H Elsea
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
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Gupta D, Bijarnia-Mahay S, Kohli S, Saxena R, Puri RD, Shigematsu Y, Yamaguchi S, Sakamoto O, Gupta N, Kabra M, Thakur S, Deb R, Verma IC. Seventeen Novel Mutations in PCCA and PCCB Genes in Indian Propionic Acidemia Patients, and Their Outcomes. Genet Test Mol Biomarkers 2016; 20:373-82. [PMID: 27227689 DOI: 10.1089/gtmb.2016.0017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
AIMS The goal of this study was to identify mutations in the propionyl-CoA carboxylase alpha subunit (PCCA) and propionyl-CoA carboxylase beta subunit (PCCB) genes, and to assess their effects on propionic academia (PA) patients. METHODOLOGY Twenty-five Indian children with PA were enrolled in this study. Bidirectional Sanger sequencing was performed on both the coding and flanking regions of the PCCA and PCCB genes and the chromatograms were analyzed. Bioinformatic tools were used to classify novel variations into pathogenic or benign. RESULTS The majority of the cases (19/25, 76%) were of the early-onset (<90 days of age) type and 5 were of the late-onset type. The majority of patients had mutations in the PCCA gene (18/25). A total of 26 mutations were noted: 20 in the PCCA gene and 6 in PCCB gene. Seventeen mutations were novel (14 in PCCA and 3 in PCCB). The SNP c.937C>T (p.Arg313Ter), was noted in 9/36 (25%) alleles in the PCCA gene. All of the children were symptomatic and only three survived who are doing well with no major disabilities. CONCLUSION The spectrum of mutations in the PCCA and PCCB genes among Indians is distinct from other populations. The absence of a common mutation signifies the heterogeneity and admixture of various subpopulations. These findings also suggest that individuals of Indian origin may not benefit from the mutation-based "carrier screening panels" offered by many genetic laboratories.
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Affiliation(s)
- Deepti Gupta
- 1 Center of Medical Genetics, Sir Ganga Ram Hospital , New Delhi, India .,2 Amity Institute of Biotechnology, Amity University , Noida, India
| | | | - Sudha Kohli
- 1 Center of Medical Genetics, Sir Ganga Ram Hospital , New Delhi, India
| | - Renu Saxena
- 1 Center of Medical Genetics, Sir Ganga Ram Hospital , New Delhi, India
| | - Ratna Dua Puri
- 1 Center of Medical Genetics, Sir Ganga Ram Hospital , New Delhi, India
| | | | - Seiji Yamaguchi
- 4 Department of Pediatrics, Shimane University School of Medicine , Izumo, Japan
| | - Osamu Sakamoto
- 5 Department of Pediatrics, Tohoku University School of Medicine , Sendai, Japan
| | - Neerja Gupta
- 6 Department of Pediatrics, All India Institute of Medical Sciences , New Delhi, India
| | - Madhulika Kabra
- 6 Department of Pediatrics, All India Institute of Medical Sciences , New Delhi, India
| | - Seema Thakur
- 7 Department of Genetics and Fetal Medicine, Fortis Hospitals , Delhi, India
| | - Roumi Deb
- 2 Amity Institute of Biotechnology, Amity University , Noida, India
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Evidence for catabolic pathway of propionate metabolism in CNS: expression pattern of methylmalonyl-CoA mutase and propionyl-CoA carboxylase alpha-subunit in developing and adult rat brain. Neuroscience 2009; 164:578-87. [PMID: 19699272 DOI: 10.1016/j.neuroscience.2009.08.028] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 08/11/2009] [Accepted: 08/12/2009] [Indexed: 11/23/2022]
Abstract
Methylmalonyl-CoA mutase (MCM) and propionyl-CoA carboxylase (PCC) are the key enzymes of the catabolic pathway of propionate metabolism and are mainly expressed in liver, kidney and heart. Deficiency of these enzymes leads to two classical organic acidurias: methylmalonic and propionic aciduria. Patients with these diseases suffer from a whole spectrum of neurological manifestations that are limiting their quality of life. Current treatment does not seem to effectively prevent neurological deterioration and pathophysiological mechanisms are poorly understood. In this article we show evidence for the expression of the catabolic pathway of propionate metabolism in the developing and adult rat CNS. Both, MCM and PCC enzymes are co-expressed in neurons and found in all regions of the CNS. Disease-specific metabolites such as methylmalonate, propionyl-CoA and 2-methylcitrate could thus be formed autonomously in the CNS and contribute to the pathophysiological mechanisms of neurotoxicity. In rat embryos (E15.5 and E18.5), MCM and PCC show a much higher expression level in the entire CNS than in the liver, suggesting a different, but important function of this pathway during brain development.
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Kaya N, Al-Owain M, Albakheet A, Colak D, Al-Odaib A, Imtiaz F, Coskun S, Al-Sayed M, Al-Hassnan Z, Al-Zaidan H, Meyer B, Ozand P. Array comparative genomic hybridization (aCGH) reveals the largest novel deletion in PCCA found in a Saudi family with propionic acidemia. Eur J Med Genet 2008; 51:558-65. [PMID: 18790721 DOI: 10.1016/j.ejmg.2008.08.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Accepted: 08/11/2008] [Indexed: 10/21/2022]
Abstract
Propionic acidemia is a metabolic disorder (OMIM 606054) caused by deficiency of the propionyl-coenzyme A (CoA) carboxylase, which subsequently results in accumulation of propionic acid. Patients may initially present with poor feeding, vomiting, loss of appetite, hypotonia, and lethargy. Later, most children will show different degrees of motor, social and language delay even more serious medical problems, including heart abnormalities, seizures, coma, and possibly death. Two siblings affected with propionic acidemia were screened for putative mutations in PCCA and PCCB genes coding alpha and beta subunits of propionyl-coenzyme A (CoA) carboxylase, respectively. Both patients had a mild-severe form of propionic acidemia. The investigations using PCR, long-PCR, array comparative genomic hybridization (aCGH), and sequencing techniques showed a approximately 73kb deletion extending from intron 16 to intron 19 and an 18bp insertion at the distal end of the deletion in PCCA gene. The deletion so far is the largest gross change reported in the literature for the PCCA gene.
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Affiliation(s)
- Namik Kaya
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia.
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Desviat LR, Pérez B, Pérez-Cerdá C, Rodríguez-Pombo P, Clavero S, Ugarte M. Propionic acidemia: mutation update and functional and structural effects of the variant alleles. Mol Genet Metab 2004; 83:28-37. [PMID: 15464417 DOI: 10.1016/j.ymgme.2004.08.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2004] [Revised: 07/27/2004] [Accepted: 08/02/2004] [Indexed: 12/22/2022]
Abstract
Mutations in the PCCA or PCCB genes, encoding both subunits of propionyl-CoA carboxylase, result in propionic acidemia, a life-threatening inborn error of metabolism with autosomal recessive inheritance. To date, 41 mutations in the PCCA gene and 54 in the PCCB gene have been reported, most of them single base substitutions causing amino acid replacements, and a variety of small insertions and deletions and splicing defects. A greater heterogeneity is observed in the PCCA gene, specially in Caucasians, with no prevalent mutations, while in the Japanese population three mutations account for more than half of the alleles studied. For the PCCB gene a limited number of mutations is responsible for the majority of the alleles characterized in both Caucasian and Oriental populations. These two populations show a different mutational spectrum, only sharing some involving CpG dinucleotides probably as recurrent mutational events. Functional characterization of the mutant missense alleles has been accomplished using different prokaryotic and eukaryotic systems, and the structural consequences have been analyzed in the available crystal models. For the PCCA gene, the main molecular effect of the expressed mutations is related to protein instability, except two mutations in the active site predictably affecting ATP binding. In the PCCB gene the majority of the analyzed mutations are predicted to alter the active site conformation resulting in diminished activity. A few carboxy-terminal PCCB mutations affect the interaction between subunits and the assembly with PCCA to form a functional PCC oligomer. The amount of normal transcripts resulting from some PCCA and PCCB splicing mutations has also been analyzed. Overall, the data generated from the expression analysis reveal potential genotype-phenotype correlations for this clinically heterogeneous disorder.
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Affiliation(s)
- L R Desviat
- Centro de Biología Molecular "Severo Ochoa" CSIC-UAM, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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Sloane V, Waldrop GL. Kinetic characterization of mutations found in propionic acidemia and methylcrotonylglycinuria: evidence for cooperativity in biotin carboxylase. J Biol Chem 2004; 279:15772-8. [PMID: 14960587 DOI: 10.1074/jbc.m311982200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Acetyl-CoA carboxylase catalyzes the committed step in fatty acid synthesis in all plants, animals, and bacteria. The Escherichia coli form is a multifunctional enzyme consisting of three separate proteins: biotin carboxylase, carboxyltransferase, and the biotin carboxyl carrier protein. The biotin carboxylase component, which catalyzes the ATP-dependent carboxylation of biotin using bicarbonate as the carboxylate source, has a homologous functionally identical subunit in the mammalian biotin-dependent enzymes propionyl-CoA carboxylase and 3-methylcrotonyl-CoA carboxylase. In humans, mutations in either of these enzymes result in the metabolic deficiency propionic acidemia or methylcrotonylglycinuria. The lack of a system for structure-function studies of these two biotin-dependent carboxylases has prevented a detailed analysis of the disease-causing mutations. However, structural data are available for E. coli biotin carboxylase as is a system for its overexpression and purification. Thus, we have constructed three site-directed mutants of biotin carboxylase that are homologous to three missense mutations found in propionic acidemia or methylcrotonylglycinuria patients. The mutants M169K, R338Q, and R338S of E. coli biotin carboxylase were selected for study to mimic the disease-causing mutations M204K and R374Q of propionyl-CoA carboxylase and R385S of 3-methylcrotonyl-CoA carboxylase. These three mutants were subjected to a rigorous kinetic analysis to determine the function of the residues in the catalytic mechanism of biotin carboxylase as well as to establish a molecular basis for the two diseases. The results of the kinetic studies have revealed the first evidence for negative cooperativity with respect to bicarbonate and suggest that Arg-338 serves to orient the carboxyphosphate intermediate for optimal carboxylation of biotin.
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Affiliation(s)
- Valerie Sloane
- Division of Biochemistry and Molecular Biology, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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Pérez B, Desviat LR, Rodríguez-Pombo P, Clavero S, Navarrete R, Perez-Cerdá C, Ugarte M. Propionic acidemia: identification of twenty-four novel mutations in Europe and North America. Mol Genet Metab 2003; 78:59-67. [PMID: 12559849 DOI: 10.1016/s1096-7192(02)00197-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Propionic acidemia is an inherited metabolic disease caused by the deficiency of the mitochondrial protein propionyl-CoA carboxylase (PCC), one of the four biotin-dependent enzymes. PCC is a multimeric protein composed of two different alpha- and beta-PCC subunits, nuclearly encoded by the PCCA and PCCB genes, respectively. Mutations in either gene cause the clinically heterogeneous disease propionic acidemia. In this work we describe the mutational analysis of PCCA and PCCB deficient patients from different European countries (Spain, Italy, Belgium, Croatia, and Austria) and from America (mainly USA). We report 24 novel PA mutations, nine affecting the PCCA gene and 15 affecting the PCCB gene. They include six missense mutations, one nonsense mutation, one point exonic mutation affecting splicing, seven splicing mutations affecting splice sequences, and nine short insertions or deletions, only two in-frame. We have found a highly heterogenous spectrum of PCCA mutations, most of the PCCA deficient patients are homozygous carrying a unique genotype. The PCCA mutational spectrum includes a high proportion of short insertions or deletions affecting one nucleotide. In the PCCA mutant alleles analyzed we have also found one single nucleotide change, a novel nonsynonymous SNP. On the other hand, the PCCB deficient patients carry a more reduced spectrum of mutations, 50% of them are missense. This work represents an extensive update of the mutational study of propionic acidemia providing important information about the worldwide distribution of PA mutations and representing another essential part in the study of the phenotype-genotype correlations for the prediction of the metabolic outcome and for the implementation of treatments tailored to each PA patient.
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Affiliation(s)
- B Pérez
- Centro de Biología Molecular "Severo Ochoa," Facultad de Ciencias, Universidad Autònoma de Madrid, CSIC-UAM, Madrid, Spain
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13
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Clavero S, Martínez MA, Pérez B, Pérez-Cerdá C, Ugarte M, Desviat LR. Functional characterization of PCCA mutations causing propionic acidemia. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1588:119-25. [PMID: 12385775 DOI: 10.1016/s0925-4439(02)00155-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Propionic acidemia (PA, MIM 232000 and 232050) is caused by a deficiency of mitochondrial biotin-dependent propionyl-CoA carboxylase (PCC, EC 6.4.1.3), a heteropolymeric enzyme composed of alpha and beta subunits, which are encoded by the PCCA and PCCB genes, respectively. The PCCA protein (alpha subunit) is responsible for the formation of carboxybiotin upon hydrolysis of ATP and contains a C-terminal biotin-binding domain and a biotin carboxylase domain, defined by homology with other biotin-dependent carboxylases, some of them characterized structurally. More than 24 mutations have been found in the PCCA gene in patients with PA, among them 14 missense mutations and one in-frame deletion, for which the precise molecular effect is unknown. In this study, we have established the pathogenicity of 11 PCCA mutations (10 missense and an in-frame deletion) by expression studies in deficient fibroblasts and in a cell-free in vitro system, and analyzed the effect of each mutation on PCC activity, protein stability and domain structure. The results show that most mutant proteins show an increased turnover and are functionally deficient, suggesting that the structural alterations they cause are incompatible with normal assembly to produce a stable, functional PCC oligomer. These results are discussed in the context of the genotype-phenotype correlations in PCCA-deficient PA patients.
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Affiliation(s)
- Sonia Clavero
- Dpto. Biología Molecular, Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain
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14
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Chloupkova M, Maclean KN, Alkhateeb A, Kraus JP. Propionic acidemia: analysis of mutant propionyl-CoA carboxylase enzymes expressed in Escherichia coli. Hum Mutat 2002; 19:629-40. [PMID: 12007220 DOI: 10.1002/humu.10085] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Deficiency of propionyl-CoA carboxylase (PCC) results in propionic acidemia, an autosomal recessive disorder characterized by ketoacidosis sufficiently severe to cause neonatal death. PCC is involved in the catabolism of branched-chain amino acids, odd-chain fatty acids, and cholesterol. The enzyme is a biotin-dependent mitochondrial protein composed of two heterologous subunits arranged into an 800-kDa alpha(6 )beta(6) dodecameric structure. Approximately 60 mutations have been reported in the nuclear genes PCCA and PCCB that encode the two PCC subunits. The vast majority of these mutations have not been examined at the protein level. We present an initial characterization of 13 mutations located in exons 1, 3-7, and 12-14 of PCCB. After expression in E. coli, these recombinant mutant enzymes were analyzed for stability, biotinylation, alpha-beta subunit interaction, and activity. Our results show a functional dichotomy in these PCCB mutations with some mutants (R44P, S106R, G131R, G198D, V205D, I408del, and M442T) capable of varying degrees of assembly but forming catalytically inactive PCC proteins. Other PCCB mutants (R165W, E168K, D178H, P228L, and R410W) that are PCC deficient in patient-derived fibroblasts, were found to be capable of expressing wild-type level PCC activity when assembled in our chaperone-assisted E. coli expression system. This result indicates that these mutations exert their pathogenic effect due to an inability to assemble correctly in patients' cells. This initial screen has identified a range of mutant PCC proteins that are sufficiently stable to be purified and subsequently used for structure-function analysis to further elucidate the complex relationship between genotype and phenotype in propionic acidemia.
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Affiliation(s)
- Maja Chloupkova
- Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado, USA
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15
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Campeau E, Desviat LR, Leclerc D, Wu X, Pérez B, Ugarte M, Gravel RA. Structure of the PCCA gene and distribution of mutations causing propionic acidemia. Mol Genet Metab 2001; 74:238-47. [PMID: 11592820 DOI: 10.1006/mgme.2001.3210] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Propionyl-CoA carboxylase (PCC, EC 6.4.1.3) is a mitochondrial, biotin-dependent enzyme that functions in the catabolism of branched-chain amino acids, fatty acids with odd-numbered chain lengths, and other metabolites. It catalyzes the ATP-dependent carboxylation of propionyl-CoA to d-methylmalonyl-CoA. PCC is composed of two types of subunits, likely as alpha4beta4 or alpha6beta6, with the alpha subunit containing the covalently bound biotin prosthetic group. A genetic deficiency of PCC activity causes propionic acidemia, a potentially fatal disease with onset in severe cases in the newborn period. Affected patients may have mutations of either the PCCA or PCCB gene. In this study, we have determined the structure of the human PCCA gene which, at the present time, is only partially represented in the databases. Based on reported ESTs and confirmed by RT-PCR, we also redefine the translation initiation codon to a position 75 nucleotides upstream of the currently accepted initiation codon. We show the distribution of mutations, including three identified in this study, and renumber all reported mutations to count from the new initiation codon. The gene spans more than 360 kb and consists of 24 exons ranging from 37 to 335 bp in length. The introns range in size from 104.bp to 66 kb. We have also determined the nucleotide sequence of approximately 1 kb of the 5'-flanking region upstream of the ATG translation initiation site. The proximal 400 bp of the 5'-flanking region shows a high G + C content (67%) and is part of a putative 1-kb CpG island that extends into exon 1 and part of intron 1. The putative promoter lacks a TATA box but contains two AP-1 sites and a conservatively defined consensus GC box, the latter characteristic of the core binding sequence of the Sp1 transcription factor.
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Affiliation(s)
- E Campeau
- Department of Biology, McGill University Health Centre, Montreal, H3H 1P3, Canada
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16
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Ugarte M, Pérez-Cerdá C, Rodríguez-Pombo P, Desviat LR, Pérez B, Richard E, Muro S, Campeau E, Ohura T, Gravel RA. Overview of mutations in the PCCA and PCCB genes causing propionic acidemia. Hum Mutat 1999; 14:275-82. [PMID: 10502773 DOI: 10.1002/(sici)1098-1004(199910)14:4<275::aid-humu1>3.0.co;2-n] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Propionic acidemia is an inborn error of metabolism caused by a deficiency of propionyl-CoA carboxylase, a heteropolymeric mitochondrial enzyme involved in the catabolism of branched chain amino acids, odd-numbered chain length fatty acids, cholesterol, and other metabolites. The enzyme is composed of alpha and beta subunits which are encoded by the PCCA and PCCB genes, respectively. Mutations in both genes can cause propionic acidemia. The identification of the responsible gene, previous to mutation analysis, can be performed by complementation assay or, in some instances, can be deduced from peculiarities relevant to either gene, including obtaining normal enzyme activity in the parents of many patients with PCCB mutations, observing combined absence of alpha and beta subunits by Western blot of many PCCA patients, as well as conventional mRNA-minus result of Northern blots for either gene or beta subunit deficiency in PCCB patients. Mutations in both the PCCA and PCCB genes have been identified by sequencing either RT-PCR products or amplified exonic fragments, the latter specifically for the PCCB gene for which the genomic structure is available. To date, 24 mutations in the PCCA gene and 29 in the PCCB gene have been reported, most of them single base substitutions causing amino acid replacements and a variety of splicing defects. A greater heterogeneity is observed in the PCCA gene-no mutation is predominant in the populations studied-while for the PCCB gene, a limited number of mutations is responsible for the majority of the alleles characterized in both Caucasian and Oriental populations. These two populations show a different spectrum of mutations, only sharing some involving CpG dinucleotides, probably as recurrent mutational events. Future analysis of the mutations identified, of their functional effect and their clinical relevance, will reveal potential genotype-phenotype correlations for this clinically heterogeneous disorder.
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Affiliation(s)
- M Ugarte
- Centro de Biología Molecular "Severo Ochoa," CSIC-UAM, Madrid, Spain.
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