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Su L, Sheng H, Li X, Cai Y, Mei H, Cheng J, Li D, Lu Z, Lin Y, Chen X, Peng M, Huang Y, Zhang W, Liu L. Clinical and genetic analysis of methylmalonic aciduria in 60 patients from Southern China: a single center retrospective study. Orphanet J Rare Dis 2024; 19:198. [PMID: 38750596 PMCID: PMC11097538 DOI: 10.1186/s13023-024-03210-0] [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: 01/11/2024] [Accepted: 05/05/2024] [Indexed: 05/18/2024] Open
Abstract
BACKGROUND Methylmalonic aciduria (MMA) is a group of rare genetic metabolic disorders resulting from defects in methylmalonyl coenzyme A mutase (MCM) or intracellular cobalamin (cbl) metabolism. MMA patients show diverse clinical and genetic features across different subtypes and populations. METHODS We retrospectively recruited 60 MMA patients from a single center and diagnosed them based on their clinical manifestations and biochemical assays. We then performed genetic analysis to confirm the diagnosis and identify the causal variants. RESULTS We confirmed the common clinical manifestations of MMA reported previously. We also described four rare MMA cases with unusual symptoms or genetic variants, such as pulmonary hypertension or limb weakness in late-onset patients. We identified 15 MMACHC and 26 MMUT variants in 57 patients, including 6 novel MMUT variants. Two patients had only one MMAA variant each, and one patient had mild MMA due to mitochondrial DNA depletion syndrome caused by a SUCLA2 variant. Among 12 critically ill patients, isolated MMA was associated with higher C3, blood ammonia, and acidosis, while combined MMA was linked to hydrocephalus on skull MRI. MMACHC c.658-660delAAG and MMUT c.1280G > A variants were correlated with more severe phenotypes. CONCLUSIONS Our study demonstrates the clinical and genotypic heterogeneity of MMA patients and indicates that metabolic screening and genetic analysis are useful tools to identify rare cases.
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Affiliation(s)
- Ling Su
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Huiying Sheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Xiuzhen Li
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Yanna Cai
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Huifen Mei
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Jing Cheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Duan Li
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Zhikun Lu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Yunting Lin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Xiaodan Chen
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Minzhi Peng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Yonglan Huang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China
| | - Wen Zhang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China.
| | - Li Liu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Tianhe District, Guangzhou, Guangdong, 510623, P.R. China.
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Zhang X, Xu X, Shu J, Zhi X, Wang H, Dong Y, Sheng W, Li D, Meng Y, Cai C. A novel MMUT splicing variant causing mild methylmalonic acidemia phenotype. Heliyon 2024; 10:e26912. [PMID: 38455531 PMCID: PMC10918191 DOI: 10.1016/j.heliyon.2024.e26912] [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: 02/09/2023] [Revised: 02/21/2024] [Accepted: 02/21/2024] [Indexed: 03/09/2024] Open
Abstract
Objectives Methylmalonic acidemia (MMA) is a rare inborn genetic disorder that is characterized by increased levels of methylmalonic acid in blood plasma and urine. Isolated methylmalonic acidemia is one of the most common types of MMA and is caused by mutations in the gene encoding methyl-malonyl coenzyme A mutase (MMUT). In this study, we investigated the possible mechanisms underlying the symptoms of isolated MMA in a patient by molecular analysis. Methods PCR amplification and Sanger sequencing analysis was performed to identify variants in the MMUT gene in the proband and his family. Furthermore, minigene constructs were generated to validate the splicing defects in the MMUT gene variant identified in the proband. Results The 3-year-old patient was admitted to the hospital with symptoms of MMA, including fever, convulsions, and vomiting. He showed metabolic acidosis, high levels of methylmalonic acid in blood and urine, and normal blood homocysteine levels. Genetic analysis demonstrated that the patient was a compound heterozygous carrier of two variants in the MMUT gene: a missense c.278G > A variant that has already been reported in a patient with the severe mut⁰ phenotype; and a novel splice site variant c.2125-2A > G. RT-PCR analysis showed that, while the novel variant clearly alters splicing, a minor amount of a full-length transcript is generated, suggesting that a wild-type protein may be produced although at a lower quantitative level. The patient's condition improved after treatment with vitamin B12. Serious complications were not reported during follow-up at age 5. Conclusions We identified a novel splice site variant that partially disrupts normal splicing of the MMUT pre-mRNA. Production of a reduced amount of full-length transcript is responsible for the mild clinical phenotype observed in this patient. Functional studies have proven useful in exploring the genotype-phenotype association and in providing guidance for the genetic diagnosis of MMA.
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Affiliation(s)
- Xinjie Zhang
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Pediatric Research Institute, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Xiaowei Xu
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Pediatric Research Institute, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Jianbo Shu
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Pediatric Research Institute, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Xiufang Zhi
- Graduate College of Tianjin Medical University, No. 22 Qixiangtai Road, Heping District, Tianjin, 300070, China
| | - Hong Wang
- Department of Neurology, Tianjin Children's Hospital, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Yan Dong
- Graduate College of Tianjin Medical University, No. 22 Qixiangtai Road, Heping District, Tianjin, 300070, China
| | - Wenchao Sheng
- Graduate College of Tianjin Medical University, No. 22 Qixiangtai Road, Heping District, Tianjin, 300070, China
| | - Dong Li
- Department of Neurology, Tianjin Children's Hospital, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Yingtao Meng
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Pediatric Research Institute, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
| | - Chunquan Cai
- Tianjin Children's Hospital (Children's Hospital of Tianjin University), No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Pediatric Research Institute, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, No. 238 Longyan Road, Beichen District, Tianjin, 300134, China
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Guo Y, Zhu X, Song L, Wang Y, Gao J, Yuan E, Yu H, Fang Y, Shi Q, Zhao D, Zhang L. Genetic analysis of isolated methylmalonic acidemia in Henan, China: c.1663G>A variant of MMUT prevalent in the Henan population. Clin Chim Acta 2024; 553:117729. [PMID: 38128819 DOI: 10.1016/j.cca.2023.117729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 12/12/2023] [Accepted: 12/16/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND Methylmalonic acidemia (MMA) is the most common organic acidemia in China, and isolated MMA accounts for approximately 30 % of all types of MMA. Common variants of the MMUT gene vary greatly around the world. The present study aims to determine the high-frequency and novel genetic variants of the MMUT gene in the Henan population of China and evaluate the prognosis of patients carrying the c.1663G>A (p.Ala555Thr) variant. METHODS We performed next-generation sequencing for 41 patients with isolated MMA screened by tandem mass spectrometry (MS/MS) and analysed the genetic results. We also evaluated the prognosis of patients with the c.1663G>A variant. We used Jalview software for multispecies sequence alignment and Missense3D and DynaMut to predict the protein function of the detected novel variants. RESULTS A total of 43 variants from 41 patients with isolated MMA were detected, of which c.1663G>A (14.63 %), c.729_730insTT (10.98 %), and c.1106G>A (8.53 %) are high-frequency variants of the MMUT gene in the Henan population. The patients carrying the c.1663G>A variant tended to be responsive to vitamin B12, have a low mortality rate. We also identified 5 novel variants (c.479C>T, c.811G>C, c.965T>A, c.1142G>A and c.1667C>T). CONCLUSION The rare variant c.1663G>A is prevalent in the Henan population, and infants with this variant tend to have good prognosis. Our findings, especially novel variants, will help broaden the spectrum of genetic variants and facilitate clinical diagnosis and genetic counselling for affected families.
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Affiliation(s)
- Yaqing Guo
- Department of Laboratory Medicine, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China; Zhengzhou Key Laboratory for In Vitro Diagnosis of Hypertensive Disorders of Pregnancy, Zhengzhou 450052, People's Republic of China.
| | - Xinyun Zhu
- Department of Henan Newborn Screening Center, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China.
| | - Liying Song
- Department of Laboratory Medicine, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China; Zhengzhou Key Laboratory for In Vitro Diagnosis of Hypertensive Disorders of Pregnancy, Zhengzhou 450052, People's Republic of China.
| | - Yu Wang
- Department of Laboratory Medicine, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China; Zhengzhou Key Laboratory for In Vitro Diagnosis of Hypertensive Disorders of Pregnancy, Zhengzhou 450052, People's Republic of China.
| | - Jinshuang Gao
- Department of Laboratory Medicine, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China; Zhengzhou Key Laboratory for In Vitro Diagnosis of Hypertensive Disorders of Pregnancy, Zhengzhou 450052, People's Republic of China.
| | - Erfeng Yuan
- Department of Laboratory Medicine, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China; Zhengzhou Key Laboratory for In Vitro Diagnosis of Hypertensive Disorders of Pregnancy, Zhengzhou 450052, People's Republic of China.
| | - Haiyang Yu
- Department of Laboratory Medicine, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China; Zhengzhou Key Laboratory for In Vitro Diagnosis of Hypertensive Disorders of Pregnancy, Zhengzhou 450052, People's Republic of China.
| | - Yang Fang
- Department of Laboratory Medicine, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China; Zhengzhou Key Laboratory for In Vitro Diagnosis of Hypertensive Disorders of Pregnancy, Zhengzhou 450052, People's Republic of China
| | - Qianqian Shi
- Department of Laboratory Medicine, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China; Zhengzhou Key Laboratory for In Vitro Diagnosis of Hypertensive Disorders of Pregnancy, Zhengzhou 450052, People's Republic of China.
| | - Dehua Zhao
- Department of Henan Newborn Screening Center, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China.
| | - Linlin Zhang
- Department of Laboratory Medicine, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, People's Republic of China; Zhengzhou Key Laboratory for In Vitro Diagnosis of Hypertensive Disorders of Pregnancy, Zhengzhou 450052, People's Republic of China.
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4
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Liang L, Ling S, Yu Y, Shuai R, Qiu W, Zhang H, Shen L, Wu S, Wei H, Chen Y, Yang C, Xu P, Chen X, Zou H, Feng J, Niu T, Hu H, Gong Z, Chen T, Zhan X, Gu X, Han L. Evaluation of the clinical, biochemical, genotype and prognosis of mut-type methylmalonic acidemia in 365 Chinese cases. J Med Genet 2023; 61:8-17. [PMID: 37316190 DOI: 10.1136/jmg-2022-108682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 05/28/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND Methylmalonic acidemia (MMA), which results from defects in methylmalonyl-CoA mutase (mut type) or its cofactor, is the most common inherited organic acid metabolic disease in China. This study aimed to investigate the phenotype and genotype of mut-type MMA in Chinese patients. METHODS We recruited 365 patients with mut-type MMA; investigated their disease onset, newborn screening (NBS) status, biochemical metabolite levels, gene variations and prognosis; and explored the relationship between phenotype and genotype. RESULTS There were 152 patients diagnosed by tandem mass spectrometry (MS/MS) expanded NBS, 209 patients diagnosed because of disease onset without NBS and 4 cases diagnosed because of sibling diagnosis. The median age of onset was 15 days old, with a variety of symptoms without specificity. Urinary levels of methylmalonic acid and methylcitric acid (MCA) decreased after treatment. Regarding the prognosis, among the 152 patients with NBS, 50.6% were healthy, 30.3% had neurocognitive impairment and/or movement disorders and 13.8% died. Among the 209 patients without NBS, 15.3% were healthy, 45.9% had neurocognitive impairment and/or movement disorders and 33.0% died. In total, 179 variants were detected in the MMUT gene, including 52 novel variations. c.729_730insTT, c.1106G>A, c.323G>A, c.914T>C and c.1663G>A were the five most frequent variations. The c.1663G>A variation led to a milder phenotype and better prognosis. CONCLUSION There is a wide spectrum of variations in the MMUT gene with several common variations. Although the overall prognosis of mut-type MMA was poor, participation in MS/MS expanded NBS, vitamin B12 responsive and late onset are favourable factors for the prognosis.
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Affiliation(s)
- Lili Liang
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
| | - Shiying Ling
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
| | - Yue Yu
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
| | - Ruixue Shuai
- Department of Pediatrics, Shanghai Changzheng Hospital, Shanghai, China
| | - Wenjuan Qiu
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
| | - Huiwen Zhang
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
| | - Linghua Shen
- Center of Neonatal Disease Screening, Henan Children's Hospital, Zhengzhou, Henan, China
| | - Shengnan Wu
- Center of Neonatal Disease Screening, Henan Children's Hospital, Zhengzhou, Henan, China
| | - Haiyan Wei
- Center of Neonatal Disease Screening, Henan Children's Hospital, Zhengzhou, Henan, China
| | - Yongxing Chen
- Center of Neonatal Disease Screening, Henan Children's Hospital, Zhengzhou, Henan, China
| | - Chiju Yang
- Center of Neonatal Disease Screening, Jining Maternal and Child Health Care Hospital, Jining, China
| | - Peng Xu
- Center of Neonatal Disease Screening, Jining Maternal and Child Health Care Hospital, Jining, China
| | - Xigui Chen
- Center of Neonatal Disease Screening, Jining Maternal and Child Health Care Hospital, Jining, China
| | - Hui Zou
- Center of Neonatal Disease Screening, Jinan Maternal and Child Health Care Hospital, Jinan, China
| | - Jizhen Feng
- Center of Neonatal Disease Screening, Shijiazhuang Maternal and Child Health Care Hospital, Shijiazhuang, China
| | - Tingting Niu
- Center of Neonatal Disease Screening, Shandong Maternal and Child Health Care Hospital, Jinan, China
| | - Haili Hu
- Center of Neonatal Disease Screening, Hefei Maternal and Child Health Care Hospital, Hefei, China
| | - Zhuwen Gong
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
| | - Ting Chen
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
| | - Xia Zhan
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
| | - Xuefan Gu
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
| | - Lianshu Han
- Department Of Pediatric Endocrinology/Genetics, Shanghai Institute For Pediatric Research, Xinhua Hospital Affiliated To Shanghai Jiao Tong University School Of Medicine, Shanghai, China
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MUT gene variants in patients with methylmalonic acidemia in Bangladeshi population and their distinguishing metabolic profiles. Meta Gene 2021. [DOI: 10.1016/j.mgene.2021.100954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Liang L, Shuai R, Yu Y, Qiu W, Shen L, Wu S, Wei H, Chen Y, Yang C, Xu P, Chen X, Zou H, Feng J, Niu T, Hu H, Ye J, Zhang H, Lu D, Gong Z, Zhan X, Ji W, Yu Y, Gu X, Han L. A rare mutation c.1663G > A (p.A555T) in the MMUT gene associated with mild clinical and biochemical phenotypes of methylmalonic acidemia in 30 Chinese patients. Orphanet J Rare Dis 2021; 16:22. [PMID: 33413471 PMCID: PMC7792044 DOI: 10.1186/s13023-020-01632-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 11/27/2020] [Indexed: 01/12/2023] Open
Abstract
Background Methylmalonic acidemia is an inherited organic acid metabolic disease. It involves multiple physiological systems and has variable manifestations. The primary causative gene MMUT carries wide range of mutations, and one of them, c.1663G > A (p.A555T), is considered to be a rare type, which is seen more frequently in Asian than other populations. So far, little is known about the clinical features of patients carrying this mutation. In the present study, we aimed to define the clinical and biochemical features of the patients with this genotype. Methods Among 328 mut type methylmalonic acidemia patients from multiple hospitals in China, we collected 30 compound heterozygous patients sharing the mutation c.1663G > A (p.A555T) in the MMUT gene. Their clinical characteristics and biochemical index were described in detail and compared with methylmalonic acidemia patients without this variant. Results Most of these patients were diagnosed via newborn screening (26/30), treated in a timely manner, and kept healthy (24/30). Disease onset occurred in 7 patients. Developmental delay or intellectual impairment occurred in 4 patients. 100% of these patients (29/29) were responsive to Vitamin B12 administration. The blood propionylcarnitine, blood propionylcarnitine/acetylcarnitine ratio, urinary methylmalonic acid, urinary methylcitric acid before and after treatment in c.1663G > A (p.A555T) carrying patients were much lower than those in non-c.1663G > A (p.A555T) carrying patients. Conclusion Compared to patients with other mutations in the MMUT gene, patients with the c.1663G > A (p.A555T) mutation showed later onset, milder clinical phenotype, lighter biochemical abnormalities, better vitamin B12 responsiveness, lower morbidity, easier metabolic control, and thereby better prognosis. Newborn screening project plays an important role in early diagnosis, treatment, and prognosis of these patients.
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Affiliation(s)
- Lili Liang
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ruixue Shuai
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yue Yu
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wenjuan Qiu
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Linghua Shen
- Department of Pediatric Endocrinology and Genetics, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, China
| | - Shengnan Wu
- Department of Pediatric Endocrinology and Genetics, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, China
| | - Haiyan Wei
- Department of Pediatric Endocrinology and Genetics, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, China
| | - Yongxing Chen
- Department of Pediatric Endocrinology and Genetics, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, China
| | - Chiju Yang
- Center of Neonatal Disease Screening, Jining Maternal and Child Health Care Hospital, Jining, China
| | - Peng Xu
- Center of Neonatal Disease Screening, Jining Maternal and Child Health Care Hospital, Jining, China
| | - Xigui Chen
- Center of Neonatal Disease Screening, Jining Maternal and Child Health Care Hospital, Jining, China
| | - Hui Zou
- Center of Neonatal Disease Screening, Jinan Maternal and Child Health Care Hospital, Jinan, China
| | - Jizhen Feng
- Center of Neonatal Disease Screening, Shijiazhuang Maternal and Child Health Care Hospital, Shijiazhuang, China
| | - Tingting Niu
- Center of Neonatal Disease Screening, Shandong Maternal and Child Health Care Hospital, Jinan, China
| | - Haili Hu
- Center of Neonatal Disease Screening, Hefei Maternal and Child Health Care Hospital, Hefei, China
| | - Jun Ye
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Huiwen Zhang
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Deyun Lu
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhuwen Gong
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xia Zhan
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wenjun Ji
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yongguo Yu
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xuefan Gu
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lianshu Han
- Department of Pediatric Endocrinology/Genetics, Shanghai Institute for Pediatric Research, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
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7
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Leung ML, McAdoo S, Watson D, Stumm K, Harr M, Wang X, Chung CH, Mafra F, Nesbitt AI, Hakonarson H, Santani A. A Transparent Approach to Calculate Detection Rate and Residual Risk for Carrier Screening. J Mol Diagn 2021; 23:91-102. [PMID: 33349347 DOI: 10.1016/j.jmoldx.2020.10.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/05/2020] [Accepted: 10/14/2020] [Indexed: 01/25/2023] Open
Abstract
Carrier screening involves detection of carrier status for genes associated with recessive conditions. A negative carrier screening test result bears a nonzero residual risk (RR) for the individual to have an affected child. The RR depends on the prevalence of specific conditions and the detection rate (DR) of the test itself. Herein, we provide a detailed approach for calculating DR and RR. DR was calculated on the basis of the sum of disease allele frequencies (DAFs) of pathogenic variants found in published literature. As a proof of concept, DAF data for cystic fibrosis were compared with society guidelines. The DAF data calculated by this method were consistent with the published cystic fibrosis guideline. In addition, we compared DAF for four genes (ABCC8, ASPA, GAA, and MMUT) across three laboratories, and outlined the likely reasons for discrepancies between these laboratories. The utility of carrier screening is to support couples with information while making reproductive choices. Accurate development of DR and RR is therefore critical. The method described herein provides an unbiased and transparent process to collect, calculate, and report these data.
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Affiliation(s)
- Marco L Leung
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio; Department of Pathology, The Ohio State University College of Medicine, Columbus, Ohio; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio.
| | | | - Deborah Watson
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Departments of Pediatrics, The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Kallyn Stumm
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Margaret Harr
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Xiang Wang
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Christine H Chung
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Fernanda Mafra
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Addie I Nesbitt
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Hakon Hakonarson
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Departments of Pediatrics, The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Avni Santani
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Pathology and Laboratory Medicine, The University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
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8
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Han B, Nie W, Sun M, Liu Y, Cao Z. Clinical presentation, molecular analysis and follow-up of patients with mut methylmalonic acidemia in Shandong province, China. Pediatr Neonatol 2020; 61:148-154. [PMID: 31466887 DOI: 10.1016/j.pedneo.2019.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/06/2019] [Accepted: 07/24/2019] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND The mut methylmalonic acidemia (MMA) caused by the deficiency of methylmalonyl-CoA mutase (MCM) activity, which results from defects in the MUT gene. The aim of this study was to summarize the clinical and biochemical data, spectrum of mutations, treatment regime and follow-up of patients with mut MMA from Jan 2013 to Dec 2017 in Shandong province, China. METHODS Twenty patients were diagnosed with isolated mut MMA by elevated C3, C3/C2, and urine methylmalonic acid levels without hyperhomocysteinemia. The MUT gene was amplified and sequenced. Most patients received treatment with specific medical nutrition and oral l-carnitine after diagnosis. Metabolic parameters, clinical presentation and mental development were followed up. RESULTS Among 20 patients with mut MMA, 14 had clinical presentations, and 12 presented in the neonatal period. Three patients died of metabolic crises triggered by infection. Twenty-three different mutations were detected, and four mutations (c.613G > A, c.446A > G, c.920-923delTCTT and c.1359delT) were novel. Most patients received timely treatment and had favorable metabolic responses, with reductions in C3, C3/C2 and urine MMA. We obtained 16 records of DQ/IQ assessments. Six patients exhibited normal development, but ten patients suffered from neurological symptoms of varying degrees and had low DQ/IQ scores. CONCLUSION Our study contributes toward expanding the knowledge of the genetic basis of mut MMA. The c.914T > C was the most frequent mutation, and four novel mutations were detected. Patients diagnosed by newborn screening and treated at the presymptomatic stage may have better outcomes. However, these limited data do not allow any definitive statements on possible genotype-phenotype correlations that can influence the outcomes of mut MMA. Nonetheless, it is necessary for high-risk families to have early prenatal diagnoses.
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Affiliation(s)
- Bingjuan Han
- Jinan Maternal and Child Care Hospital, Jinan 250001, Shandong Province, China
| | - Wenying Nie
- Jinan Maternal and Child Care Hospital, Jinan 250001, Shandong Province, China
| | - Meng Sun
- Jinan Maternal and Child Care Hospital, Jinan 250001, Shandong Province, China
| | - Yingxia Liu
- Jinan Maternal and Child Care Hospital, Jinan 250001, Shandong Province, China; Department of Immunology, Nanjing Medical University, Nanjing 211166, Jiangsu Province, China.
| | - Zhiyang Cao
- Nanjing Jiangning Hospital, Affiliated to Nanjing Medical University, Nanjing 211100, Jiangsu Province, China.
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9
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Habibzadeh P, Tabatabaei Z, Farazi Fard MA, Jamali L, Hafizi A, Nikuei P, Salarian L, Nasr Esfahani MH, Anvar Z, Faghihi MA. Pre-implantation genetic diagnosis in an Iranian family with a novel mutation in MUT gene. BMC MEDICAL GENETICS 2020; 21:22. [PMID: 32013889 PMCID: PMC6998079 DOI: 10.1186/s12881-020-0959-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 01/22/2020] [Indexed: 12/21/2022]
Abstract
Background Methylmalonic acidemia (MMA), which is an autosomal recessive metabolic disorder, is caused by mutations in methylmalonyl-CoA mutase (MUT) gene. As a result, the conversion of methylmalonyl-CoA to succinyl-CoA is impaired in this disorder, leading to a wide range of clinical manifestations varying from no signs or symptoms to severe lethargy and metabolic crisis in newborn infants. Since identification of novel mutations in MUT gene can help discover the exact pathogenesis of MMA and also use these disease-causing mutations in prenatal diagnosis, this study was conducted to uncover the possible mutations in an Iranian couple with a deceased offspring clinically diagnosed as having organic acidemia. Moreover, to prevent the occurrence of the mutation in the next pregnancy, we took the advantage of pre-implantation genetic diagnosis (PGD), which resulted in a successful pregnancy. Case presentation The affected individual was a 15-month-old boy who passed away due to aspiration pneumonia. The child presented at the age of 3 months with lethargy, protracted vomiting, hypotonia, and decreased level of consciousness. To find the mutated gene, Next Generation Sequencing (NGS) was performed as carrier testing for the parents and the results revealed a novel (private) heterozygous missense mutation in MUT gene (c.1055A > G, p.Q352R). After performing PGD on three blastomeres, one was identified as being homozygous wild-type that was followed by successful pregnancy. Conclusions Our study identified a novel, deleterious, heterozygous missense mutation in MUT gene in a couple and helps to consider the genetic counselling and prenatal diagnosis more seriously for this family with clinical phenotypes of organic acidemia.
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Affiliation(s)
- Parham Habibzadeh
- Persian BayanGene Research and Training Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Tabatabaei
- Persian BayanGene Research and Training Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Ali Farazi Fard
- Persian BayanGene Research and Training Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Laila Jamali
- Persian BayanGene Research and Training Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Aazam Hafizi
- Persian BayanGene Research and Training Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Pooneh Nikuei
- Fertility and Infertility Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Leila Salarian
- Department of Pediatrics, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Hossein Nasr Esfahani
- Department of Reproductive Biotechnology, Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR, and Isfahan Fertility and Infertility Center, Isfahan, Iran
| | - Zahra Anvar
- Infertility Research Center, Shiraz University of Medical Sciences, Shiraz, Iran. .,Department of Obstetrics and Gynecology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Mohammad Ali Faghihi
- Persian BayanGene Research and Training Center, Shiraz University of Medical Sciences, Shiraz, Iran.
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10
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Chu TH, Chien YH, Lin HY, Liao HC, Ho HJ, Lai CJ, Chiang CC, Lin NC, Yang CF, Hwu WL, Lee NC, Lin SP, Liu CS, Hu RH, Ho MC, Niu DM. Methylmalonic acidemia/propionic acidemia - the biochemical presentation and comparing the outcome between liver transplantation versus non-liver transplantation groups. Orphanet J Rare Dis 2019; 14:73. [PMID: 30940196 PMCID: PMC6444613 DOI: 10.1186/s13023-019-1045-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 03/12/2019] [Indexed: 01/13/2023] Open
Abstract
Background Most patients with isolated methylmalonic acidemia (MMA) /propionic acidemia (PA) presenting during the neonatal period with acute metabolic distress are at risk for death and significant neurodevelopmental disability. The nationwide newborn screening for MMA/PA has been in place in Taiwan from January, 2000 and data was collected until December, 2016. Results During the study period, 3,155,263 newborns were screened. The overall incidence of MMA mutase type cases was 1/121,356 (n = 26), 1 cobalamin B was detected and that for PA cases (n = 4) was 1/788,816. The time of referral is 8.8 days for MMA patients, and 7.5 days for PA patients. The MMA mutase type patients have higher AST, ALT, and NH3 values as well as a lower pH value (p < 0.05). The mean age for liver transplantation (LT) is 402 days (range from 0.6–6.7 yr) with 16 out of 20 cases (80.0%) using living donors. The mean admission length shortened from 90.6 days/year (pre-LT) to 5.3 days/year (at 3rd year post-LT) (p < 0.0005). Similarly, the tube feeding ratio decreased from 67.8 to 0.50% (p < 0.00005). The anxiety level of the caregiver was reduced from 33.4 to 27.2 after LT (p = 0.001) and the DQ/IQ performance of the patients was improved after LT from 50 to 60.1 (p = 0.07). Conclusion MMA/PA patients with LT do survive and have reduced admission time, reduced tube feeding and the caregiver is less anxious.
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Affiliation(s)
- Tzu-Hung Chu
- Division of Genetics and Metabolism, Department of Pediatrics, Taipei Veterans General Hospital, Taipei, Taiwan.,Taiwan Medican Mission in Eswatini, Taipei, Taiwan, Republic of China
| | - Yin-Hsiu Chien
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Hsiang-Yu Lin
- Department of Pediatrics, MacKay Memorial Hospital, Taipei, Taiwan.,Mackay Junior College of Medicine, Nursing and Management, Taipei, Taiwan
| | - Hsuan-Chieh Liao
- Newborn Screening Center, The Chinese Foundation of Health, Taipei, Taiwan
| | - Huey-Jane Ho
- Section of Newborn screening, Taipei Institute of Pathology, Taipei, Taiwan
| | - Chih-Jou Lai
- Division of Rehabilitation, Department of Medical Affairs, Taipei Municipal Gan-Dau Hospital (Managed by Taipei Veterans General Hospital), Taipei, Taiwan
| | - Chuan-Chi Chiang
- Newborn Screening Center, The Chinese Foundation of Health, Taipei, Taiwan
| | - Niang-Cheng Lin
- Division of Pediatric Surgery, Department of Surgery, Taipei Veterans General, Taipei, Taiwan
| | - Chia-Feng Yang
- Division of Genetics and Metabolism, Department of Pediatrics, Taipei Veterans General Hospital, Taipei, Taiwan.,Institute of Environmental And Occupational Health Sciences, Taipei, Taiwan
| | - Wuh-Liang Hwu
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Ni-Chung Lee
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Shuan-Pei Lin
- Department of Pediatrics, MacKay Memorial Hospital, Taipei, Taiwan
| | - Chin-Su Liu
- Division of Pediatric Surgery, Department of Surgery, Taipei Veterans General, Taipei, Taiwan
| | - Rey-Heng Hu
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
| | - Ming-Chih Ho
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
| | - Dau-Ming Niu
- Division of Genetics and Metabolism, Department of Pediatrics, Taipei Veterans General Hospital, Taipei, Taiwan. .,Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan. .,The Medical Science & Techonology Building, (Room 8055) No. 201, Sec.2, Shih-Pai Road, Taipei, Taiwan, Republic of China.
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11
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Keyfi F, Abbaszadegan MR, Sankian M, Rolfs A, Orolicki S, Pournasrollah M, Alijanpour M, Varasteh A. Mutation analysis of genes related to methylmalonic acidemia: identification of eight novel mutations. Mol Biol Rep 2019; 46:271-285. [PMID: 30712249 DOI: 10.1007/s11033-018-4469-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 11/02/2018] [Indexed: 11/28/2022]
Abstract
Methylmalonic acidemia (MMA), an inherited metabolic disease, results from genetic defects in methylmalonyl-CoA mutase or any of the proteins involved in adenosylcobalamin synthesis. This enzyme is classified into several complementation groups and genotypic classes. In this work we explain the biochemical, structural and genetic analysis of 25 MMA patients, from Iran. The diagnosis was established by the measurement of propionylcarnitine in blood using tandem mass spectrometry and confirmed using a gas chromatography-flame ionization detector. Using clinical, biochemical, structural and molecular analyses we identified 15 mut MMA, three cblA, one cblB, and four cblC-deficient patients. Among mutations identified in the MUT gene (MUT) only one, the c.1874A>C (p.D625A) variant, is likely a mut- mutation. The remaining mutations are probably mut0. Here, we present the first molecular analysis of MMA in Iranian patients and have identified eight novel mutations. Four novel mutations (p.D625A, p.R326G, p.V157F, p.F379L) were seen exclusively in patients from northern Iran. One novel splice site mutation (c.2125-3C>G) in MUT and two novel mutation (p.N225M and p.A99P) in the MMAA gene were associated with patients from eastern Iran. The rs184829210 SNP was recognized only in patients with the novel c.958G>A (p.A320T) mutation. This study confirms pathogenesis of deficient enzyme activity in MUT, MMAA, MMAB, and MMACHC as previous observations. These results could act as a basis for the performance of pharmacological therapies for increasing the activity of proteins derived from these mutations.
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Affiliation(s)
- Fatemeh Keyfi
- Department of Medical Laboratory Sciences, Varastegan Institute for Medical Sciences, Mashhad, Iran.,Division of Metabolic disorders, Pardis Clinical and Genetic Laboratory, Mashhad, Iran.,Immunology Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad R Abbaszadegan
- Division of Human Genetics, Immunology Research Center, Avicenna Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mojtaba Sankian
- Immunology Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Arndt Rolfs
- Albrecht Kossel Institute for Neuroregeneration, University of Rostock, Rostock, Germany.,Chief Medical Director, Centogene AG, Rostock, Germany
| | | | - Mohammad Pournasrollah
- Non-contagious pediatric disease Research Center, Babol University of Medical Sciences, Babol, Iran
| | - Morteza Alijanpour
- Non-contagious pediatric disease Research Center, Babol University of Medical Sciences, Babol, Iran
| | - Abdolreza Varasteh
- Department of Medical Laboratory Sciences, Varastegan Institute for Medical Sciences, Mashhad, Iran. .,Division of Metabolic disorders, Pardis Clinical and Genetic Laboratory, Mashhad, Iran. .,Allergy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
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12
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Zhou W, Li H, Wang C, Wang X, Gu M. Newborn Screening for Methylmalonic Acidemia in a Chinese Population: Molecular Genetic Confirmation and Genotype Phenotype Correlations. Front Genet 2019; 9:726. [PMID: 30728829 PMCID: PMC6351470 DOI: 10.3389/fgene.2018.00726] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/22/2018] [Indexed: 12/16/2022] Open
Abstract
Background: Methylmalonic acidemia (MMA) incidence was evaluated based on newborn screening in Xuzhou from November 2015 to December 2017, and the clinical, biochemical and molecular characteristics of patients with MMA harboring MMACHC and MUT mutations were summarized. Methods: During the study, 236,368 newborns were screened for MMA by tandem mass spectrometry (MS/MS) in the Maternity and Child Health Care Hospital of Xuzhou. C3, C3/C2 and methionine, and tHcy if necessary, were measured during the first screening. Blood samples from the infants and/or their family members were used for DNA analysis. The entire coding regions of the MMACHC and MUT genes associated with MMA were sequenced by DNA MassARRAY and next-generation sequencing (NGS). Results: Eleven patients with MMACHC mutations and three with MUT mutations were identified among the 236,368 screened newborns; the estimated total incidence of MMA was 1:16,883. Among the MMA patients, two died of infection-triggered metabolic crisis approximately 3 months after birth. All the patients identified had two mutant alleles except for one individual with early-onset disease. The most common MMACHC mutation was c.609G > A. The laboratory levels of C3 and C3/C2 were elevated in MMA individuals compared to other infants. Importantly, we demonstrate that accelerated C2 degradation is related to air temperature and humidity. Conclusion: Our study reports the clinical characteristics of MMA and diagnosis through MS/MS and NGS. There was a higher incidence of MMA with homocysteinemia than of isolated MMA in Xuzhou. Insight from this study may help explain the high false-positive rate of MMA in summer.
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Affiliation(s)
- Wei Zhou
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Huizhong Li
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Chuanxia Wang
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Xiuli Wang
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
| | - Maosheng Gu
- Xuzhou Maternity and Child Health Care Hospital, Xuzhou, China
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13
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Erlich‐Hadad T, Hadad R, Feldman A, Greif H, Lictenstein M, Lorberboum‐Galski H. TAT-MTS-MCM fusion proteins reduce MMA levels and improve mitochondrial activity and liver function in MCM-deficient cells. J Cell Mol Med 2018; 22:1601-1613. [PMID: 29265583 PMCID: PMC5824393 DOI: 10.1111/jcmm.13435] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 09/25/2017] [Indexed: 12/14/2022] Open
Abstract
Methylmalonic aciduria (MMA) is a disorder of organic acid metabolism resulting from a functional defect of the mitochondrial enzyme, methylmalonyl-CoA mutase (MCM). The main treatments for MMA patients are dietary restriction of propiogenic amino acids and carnitine supplementation. Liver or combined liver/kidney transplantation has been used to treat those with the most severe clinical manifestations. Thus, therapies are necessary to help improve quality of life and prevent liver, renal and neurological complications. Previously, we successfully used the TAT-MTS-Protein approach for replacing a number of mitochondrial-mutated proteins. In this targeted system, TAT, an 11 a.a peptide, which rapidly and efficiently can cross biological membranes, is fused to a mitochondrial targeting sequence (MTS), followed by the mitochondrial mature protein which sends the protein into the mitochondria. In the mitochondria, the TAT-MTS is cleaved off and the native protein integrates into its natural complexes and is fully functional. In this study, we used heterologous MTSs of human, nuclear-encoded mitochondrial proteins, to target the human MCM protein into the mitochondria. All fusion proteins reached the mitochondria and successfully underwent processing. Treatment of MMA patient fibroblasts with these fusion proteins restored mitochondrial activity such as ATP production, mitochondrial membrane potential and oxygen consumption, indicating the importance of mitochondrial function in this disease. Treatment with the fusion proteins enhanced cell viability and most importantly reduced MMA levels. Treatment also enhanced albumin and urea secretion in a CRISPR/Cas9-engineered HepG2 MUT (-/-) liver cell line. Therefore, we suggest using this TAT-MTS-Protein approach for the treatment of MMA.
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Affiliation(s)
- Tal Erlich‐Hadad
- Department of Biochemistry and Molecular BiologyInstitute for Medical Research Israel‐Canada (IMRIC)Faculty of MedicineHebrew University of JerusalemJerusalemIsrael
| | - Rita Hadad
- Department of Biochemistry and Molecular BiologyInstitute for Medical Research Israel‐Canada (IMRIC)Faculty of MedicineHebrew University of JerusalemJerusalemIsrael
| | | | | | - Michal Lictenstein
- Department of Biochemistry and Molecular BiologyInstitute for Medical Research Israel‐Canada (IMRIC)Faculty of MedicineHebrew University of JerusalemJerusalemIsrael
| | - Haya Lorberboum‐Galski
- Department of Biochemistry and Molecular BiologyInstitute for Medical Research Israel‐Canada (IMRIC)Faculty of MedicineHebrew University of JerusalemJerusalemIsrael
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14
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Eight novel MUT loss-of-function missense mutations in Chinese patients with isolated methylmalonic academia. World J Pediatr 2017; 13:381-386. [PMID: 28101778 DOI: 10.1007/s12519-016-0085-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 02/25/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND Isolated methylmalonic acidemia is a rare autosomal recessive metabolic disorder mostly caused by mutations in the methylmalonyl coenzyme A mutase (MCM) gene (MUT). This study aimed to verify whether missense mutations in MUT in Chinese patients affect the stability and enzymatic activity of MCM. METHODS Eight Chinese patients were identified with novel mutations. Plasmids carrying the wild-type and mutated MUT cDNA were constructed and transfected into HEK293T cells for functional analyses. The expression and activity of MCM were determined by western blot and ultra-performance liquid chromatography, respectively. RESULTS All patients had high levels of blood propionylcarnitine and urinary methylmalonyl acid. By the end of the study, two patients were lost to follow-up, three died, and three survived with mental retardation. Compared to the wild-type protein, the expression levels of all missense mutations of in vitro MCM protein were decreased (P<0.05) except those for I597R, and the MCM activity of the mutations was reduced in a permissive assay. CONCLUSIONS The missense mutations L140P, A141T, G161V, W309G, I505T, Q514K, I597R and G723D affected the stability and enzymatic activity of MCM, indicating that they had a disease-causing capacity.
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15
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Abstract
Defects in the human gene encoding methylmalonyl-CoA mutase enzyme (MCM) give rise to a rare autosomal recessive inherited disorder of propionate metabolism termed mut methylmalonic acidemia (MMA). Patients with mut MMA have been divided into two subgroups: mut0 with complete loss of MCM activity and mut- with residual activity in the presence of adenosylcobalamin (AdoCbl). The disease typically presents in the first weeks or months of life and is clinically characterized by recurrent vomiting, metabolic acidosis, hyperammonemia, lethargy, poor feeding, failure to thrive and neurological deficit. To better elucidate the spectrum of mutations causing mut MMA in Saudi patients, we screened a cohort of 60 Saudi patients affected by either forms of the disease for mutations in the MUT gene. A total of 13 different mutations, including seven previously reported missense changes and six novel mutations, were detected in a homozygous state except for two compound heterozygous cases. The six novel mutations identified herein consist of three nonsense, two missense and one frameshift, distributed throughout the whole protein. This study describes for the first time the clinical and mutational spectrum of mut MMA in Saudi Arabian patients.
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16
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Clinical features and MUT gene mutation spectrum in Chinese patients with isolated methylmalonic acidemia: identification of ten novel allelic variants. World J Pediatr 2015; 11:358-65. [PMID: 26454439 DOI: 10.1007/s12519-015-0043-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 07/14/2015] [Indexed: 01/07/2023]
Abstract
BACKGROUND This study aims to study MUT gene mutation spectrum in Chinese patients with isolated methylmalonic academia (MMA) and their clinical features for the potential genotype-phenotype correlation. METHODS Forty-three patients were diagnosed with isolated MMA by elevated blood propionylcarnitine, propionylcarnitine to acetylcarnitine ratio, and urine methylmalonate without hyperhomocysteinemia. The MUT gene was amplified by polymerase chain reaction and directly sequenced. Those patients with at least one variant allele were included. The novel missense mutations were assessed by bioinformatic analysis and screened against alleles sequenced from 50 control participants. RESULTS Among the 43 patients, 38 had typical clinical presentations, and the majority (30/38) experienced earlyonset MMA. Eight patients died and seven were lost to follow-up. Twenty patients had poor outcomes and eight showed normal development. The 43 identified MUT gene mutations had at least one variant allele, whereas 35 had two mutant alleles. Of the 33 mutations reported before, eight recurrent mutations were identified in 32 patients, and c.729_730insTT (p.D244Lfs*39) was the most common (12/78) in the mutant alleles. Of the 10 novel mutations, six were missense mutations and four were premature termination codon mutations. The six novel missense mutations seemed to be pathogenic. CONCLUSIONS A total of 10 novel MUT mutations were detected in the Chinese population. c.729_730insTT (p.D244Lfs*39) was the most frequent mutation. A genotype-phenotype correlation could not be found, but the genotypic characterization indicated the need of genetic counseling for MMA patients and early prenatal diagnoses for high-risk families.
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17
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Assay for methylmalonyl coenzyme A mutase activity based on determination of succinyl coenzyme A by ultrahigh-performance liquid chromatography tandem mass spectrometry. Anal Bioanal Chem 2015; 407:5281-6. [PMID: 26018627 DOI: 10.1007/s00216-015-8753-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 04/28/2015] [Accepted: 04/29/2015] [Indexed: 10/23/2022]
Abstract
Methylmalonic acidemia (MMA) is an inherited metabolic disease. In this condition, metabolism from methylmalonyl coenzyme A (CoA) to succinyl-CoA is inhibited because of either low methylmalonyl-CoA mutase (MCM) activity or adenosylcobalamin deficiency owing to altered vitamin B12 metabolism. A high-precision assay for detecting MCM activity would facilitate not only MMA diagnosis but also the ability to determine the severity of MMA. We developed an MCM assay method based on ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) that involves the determination of succinyl-CoA, which is formed in an enzyme reaction, using peripheral lymphocytes. Using 0.05, 0.5, and 5 μmol/L succinyl-CoA, the intra-assay coefficient of variation (CV) was less than 5.2% and the inter-assay CV was less than 8.7%. The MCM activities of five healthy individuals and four patients were investigated with this assay. The MCM activities of the patients were very low in relation to those of healthy individuals. Together, these results show that the UPLC-MS/MS method is useful for a detailed MCM activity assay.
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18
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Song WS, Song BJ, Park HD, Kim WD. A Novel MUTGene Mutation Detected in a Female Infant with Methylmalonic Acidemia. NEONATAL MEDICINE 2015. [DOI: 10.5385/nm.2015.22.1.51] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- Woo Sun Song
- Department of Pediatrics, Daegu Fatima hospital, Daegu, Korea
| | - Byung Jin Song
- Department of Pediatrics, Daegu Fatima hospital, Daegu, Korea
| | - Hyung-Doo Park
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Won Duck Kim
- Department of Pediatrics, Daegu Fatima hospital, Daegu, Korea
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19
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Imataka G, Sakamoto O, Yamanouchi H, Yoshihara S, Omura-Hasegawa Y, Tajima G, Arisaka O. Novel c.2216T > C (p.I739T) mutation in exon 13 and c.1481T > A (p.L494X) mutation in exon 8 of MUT gene in a female with methylmalonic acidemia. Cell Biochem Biophys 2014; 67:185-7. [PMID: 23479330 PMCID: PMC3756855 DOI: 10.1007/s12013-013-9532-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We report herein a 1.5-year-old girl with methylmalonic acidemia (MMA) in whom two missense mutations were found: a novel I739T mutation located in exon 13 and the L494X mutation in exon 8. The results of organic acid test showed a pronounced increase in methylmalonate excretion with increased methylcitrate and 3-OH-propionate excretion, leading to a diagnosis of MMA, and Vitamin B12 administration was started. Analysis of the mut gene confirmed a T-to-A substitution at nucleotide position 1481 in exon 8 and a T-to-C substitution at nucleotide position 2216 in exon 13, leading to the amino acid isoleucine at position 739 being changed to threonine, resulting in c.2216T > C (p.I739T). The patient has now been on high-dose oral administration of Vitamin B12 and carnitine therapy (900 mg of levocarnitine chloride) for 5 years without experiencing further attacks, and her cognitive and motor development is normal. Further tests on residual enzyme activity, as well as experience with more cases, may shed light on the relationship between gene mutations and phenotypes in MMA.
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Affiliation(s)
- George Imataka
- Department of Pediatrics, School of Medicine, Dokkyo Medical University, 880 Kitakobayashi, Mibu, Shimotsuga, Tochigi, 321-0293, Japan.
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Xu S, Bhajoo SH, Jiang W. Genetic diagnosis of one family with incomplete clinical data. J Pediatr Endocrinol Metab 2013; 26:903-8. [PMID: 23729607 DOI: 10.1515/jpem-2013-0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 04/22/2013] [Indexed: 11/15/2022]
Abstract
A 6-day-old female patient suddenly died of congestive heart failure, hepatomegaly and hypoglycemic encephalopathy. Tandem mass spectrometry (MS) analysis revealed a possibility of carnitine deficiency. However, many of the clinical symptoms had not yet occurred at that time, and the clinical data was incomplete. We aim to derive a systematic procedure of identifying pathogenic mutations for similar patients. Physicians could save patients' lives with effective treatment at a much earlier stage. Direct sequencing of the exons and exon-intron boundaries of GAA, SLC25A5, CPT1, CPT2, SLC25A20 and MUT genes were performed on the parents of the patient. DNA from the blood spots of the patient was analyzed for the MUT gene. The results revealed that the patient was a compound heterozygote with MUT. c. 729_730insTT and c. 1677-1G>A. cDNA sequence demonstrated MUT c. 1677-1G>A resulting in the deletion of eight nucleotides and the introduction of 13 novel amino acids before premature termination.
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Pons V, Rolland C, Nauze M, Danjoux M, Gaibelet G, Durandy A, Sassolas A, Lévy E, Tercé F, Collet X, Mas E. A severe form of abetalipoproteinemia caused by new splicing mutations of microsomal triglyceride transfer protein (MTTP). Hum Mutat 2011; 32:751-9. [DOI: 10.1002/humu.21494] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2010] [Accepted: 02/17/2011] [Indexed: 11/09/2022]
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Watkins D, Rosenblatt DS. Inborn errors of cobalamin absorption and metabolism. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2011; 157C:33-44. [PMID: 21312325 DOI: 10.1002/ajmg.c.30288] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Derivatives of cobalamin (vitamin B(12)) are required for activity of two enzymes in humans. Adenosylcobalamin is required for activity of mitochondrial methylmalonylCoA mutase and methylcobalamin is required for activity of cytoplasmic methionine synthase. Deficiency in cobalamin, or inability to absorb cobalamin normally, can result in accumulation of methylmalonic acid and homocysteine in blood and urine. Methylmalonic acidemia can result in metabolic acidosis which in severe cases may be fatal. Hyperhomocysteinemia along with hypomethioninemia can result in hematologic (megaloblastic anemia, neutropenia, thrombocytopenia) and neurologic (subacute combined degeneration of the cord, dementia, psychosis) defects. Inborn errors affecting cobalamin absorption (inherited intrinsic factor deficiency, Imerslund–Gra¨ sbeck syndrome) and transport (transcobalamin deficiency) have been described. A series of inborn errors of intracellular cobalamin metabolism, designated cblA-cblG, have been differentiated by complementation analysis. These can give rise to isolated methylmalonic acidemia (cblA, cblB, cblD variant 2), isolated hyperhomocysteinemia (cblD variant 1, cblE, cblG) or combined methylmalonic acidemia and hyperhomocysteinemia (cblC, classic cblD, cblF). All these disorders are inherited as autosomal recessive traits. The genes underlying each of these disorders have been identified. Two other disorders, haptocorrin deficiency and transcobalamin receptor deficiency, have been described, but it is not clear that they have any consistent clinical phenotype.
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Affiliation(s)
- David Watkins
- Department of Human Genetics, McGill University, Canada.
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Buck NE, Wood L, Hu R, Peters HL. Stop codon read-through of a methylmalonic aciduria mutation. Mol Genet Metab 2009; 97:244-9. [PMID: 19427250 DOI: 10.1016/j.ymgme.2009.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2009] [Revised: 04/02/2009] [Accepted: 04/02/2009] [Indexed: 11/19/2022]
Abstract
A stop codon defect in methylmalonyl-CoA mutase (resulting in a truncated unstable protein) accounts for up to 14% of mutations identified as causes of Methylmalonic aciduria. There are currently limited treatment regimes for patients with this inherited condition. We aimed to investigate the use of stop codon read-through drugs in a genomic reporter assay cell line with a defect in the mutase gene. A single C-T base change was introduced into exon 6 of the human MUT sequence in the BAC clone RP11-463L20 resulting in an arginine residue being replaced with a TGA stop codon. An enhanced green fluorescent protein reporter gene was introduced in-frame with exon 13 of the MUT gene. The construct was transfected into HeLa cells to produce the genomic reporter assay cell line. To test the suppression of nonsense mutations, cells were incubated in the presence of different compounds for a period of 72 h then analysed by flow cytometry. Treatment of the cells with gentamicin resulted in a 1.6-fold increase in reporter protein, whilst G418 treatment resulted in no change, however the two drugs together acted synergistically to increase the production of methylmalonyl-CoA mutase 2.0-fold (confirmed by mRNA, flow cytometry and enzyme activity). Zidovudine, adefovir and cisplatin were also found to have some activity in the stop codon read-through genomic reporter assay. These results encourage further testing of compounds as well as follow up animal studies. This is the first study to demonstrate the use of stop codon read-through drugs for the potential treatment of Methylmalonic aciduria.
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Affiliation(s)
- Nicole E Buck
- Cell & Gene Therapy Group, Murdoch Childrens Research Institute, Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, Vic. 3052, Australia
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