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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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Jiang YZ, Zhou GP, Wei L, Qu W, Zeng ZG, Liu Y, Tan YL, Wang J, Zhu ZJ, Sun LY. Long-term clinical outcomes and health-related quality of life in patients with isolated methylmalonic acidemia after liver transplantation: experience from the largest cohort study in China. World J Pediatr 2024:10.1007/s12519-023-00780-0. [PMID: 38190010 DOI: 10.1007/s12519-023-00780-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 11/14/2023] [Indexed: 01/09/2024]
Abstract
BACKGROUND Liver transplantation (LT) has been proposed as a viable treatment option for selected methylmalonic acidemia (MMA) patients. However, there are still controversies regarding the therapeutic value of LT for MMA. The systematic assessment of health-related quality of life (HRQoL)-targeted MMA children before and after LT is also undetermined. This study aimed to comprehensively assess the long-term impact of LT on MMA, including multiorgan sequelae and HRQoL in children and families. METHODS We retrospectively evaluated 15 isolated MMA patients undergoing LT at our institution between June 2013 and March 2022. Pre- and post-transplant data were compared, including metabolic profiles, neurologic consequences, growth parameters, and HRQoL. To further assess the characteristics of the HRQoL outcomes in MMA, we compared the results with those of children with biliary atresia (BA). RESULTS All patients had early onset MMA, and underwent LT at a mean age of 4.3 years. During 1.3-8.2 years of follow-up, the patient and graft survival rates were 100%. Metabolic stability was achieved in all patients with liberalized dietary protein intake. There was a significant overall improvement in height Z scores (P = 0.0047), and some preexisting neurological complications remained stable or even improved after LT. On the Pediatric Quality of Life Inventory (PedsQL™) generic core scales, the mean total, physical health, and psychosocial health scores improved significantly posttransplant (P < 0.05). In the family impact module, higher mean scores were noted for all subscales post-LT, especially family function and daily activities (P < 0.01). However, the total scores on the generic core scales and transplant module were significantly lower (Cohen's d = 0.57-1.17) when compared with BA recipients. In particular, social and school functioning (Cohen's d = 0.86-1.76), treatment anxiety, and communication (Cohen's d = 0.99-1.81) were far behind, with a large effect size. CONCLUSIONS This large single-center study of the mainland of China showed an overall favorable impact of LT on isolated MMA in terms of long-term survival, metabolic control, and HRQoL in children and families. The potential for persistent neurocognitive impairment and inherent metabolic fragility requires long-term special care. Video Abstract (MP4 153780 KB).
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Affiliation(s)
- Yi-Zhou Jiang
- Department of Critical Liver Diseases, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Beijing, 110112, China
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China
| | - Guang-Peng Zhou
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China
| | - Lin Wei
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China
| | - Wei Qu
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China
| | - Zhi-Gui Zeng
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China
| | - Ying Liu
- Department of Critical Liver Diseases, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Beijing, 110112, China
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China
| | - Yu-Le Tan
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China
| | - Jun Wang
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China
| | - Zhi-Jun Zhu
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China.
| | - Li-Ying Sun
- Department of Critical Liver Diseases, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Beijing, 110112, China.
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
- Clinical Center for Pediatric Liver Transplantation, No. 101 Lu Yuan Dong Road, Tong-Zhou District, Capital Medical University, Beijing, 110112, China.
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Vockley J, Burton B, Jurecka A, Ganju J, Leiro B, Zori R, Longo N. Challenges and strategies for clinical trials in propionic and methylmalonic acidemias. Mol Genet Metab 2023; 139:107612. [PMID: 37245378 DOI: 10.1016/j.ymgme.2023.107612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/19/2023] [Accepted: 05/19/2023] [Indexed: 05/30/2023]
Abstract
Clinical trial development in rare diseases poses significant study design and methodology challenges, such as disease heterogeneity and appropriate patient selection, identification and selection of key endpoints, decisions on study duration, choice of control groups, selection of appropriate statistical analyses, and patient recruitment. Therapeutic development in organic acidemias (OAs) shares many challenges with other inborn errors of metabolism, such as incomplete understanding of natural history, heterogenous disease presentations, requirement for sensitive outcome measures and difficulties recruiting a small sample of participants. Here, we review strategies for the successful development of a clinical trial to evaluate treatment response in propionic and methylmalonic acidemias. Specifically, we discuss crucial decisions that may significantly impact success of the study, including patient selection, identification and selection of endpoints, determination of the study duration, consideration of control groups including natural history controls, and selection of appropriate statistical analyses. The significant challenges associated with designing a clinical trial in rare disease can sometimes be successfully met through strategic engagement with experts in the rare disease, seeking regulatory and biostatistical guidance, and early involvement of patients and families.
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Affiliation(s)
- Jerry Vockley
- Division Medical Genetics, Department of Pediatrics, University of Pittsburgh, School of Medicine, Center for Rare Disease Therapy, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA, USA
| | - Barbara Burton
- Ann & Robert H. Lurie Children's Hospital, Chicago, IL, USA
| | - Agnieszka Jurecka
- CoA Therapeutics, Inc., a BridgeBio company, San Francisco, CA, USA.
| | - Jitendra Ganju
- Independent Consultant to BridgeBio, San Francisco, CA, USA
| | - Beth Leiro
- Independent Consultant to BridgeBio, San Francisco, CA, USA
| | - Roberto Zori
- Department of Pediatrics, Division of Genetics and Metabolism, University of Florida, Gainesville, FL, USA
| | - Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
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Chen T, Gao Y, Zhang S, Wang Y, Sui C, Yang L. Methylmalonic acidemia: Neurodevelopment and neuroimaging. Front Neurosci 2023; 17:1110942. [PMID: 36777632 PMCID: PMC9909197 DOI: 10.3389/fnins.2023.1110942] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/12/2023] [Indexed: 01/27/2023] Open
Abstract
Methylmalonic acidemia (MMA) is a genetic disease of abnormal organic acid metabolism, which is one of the important factors affecting the survival rate and quality of life of newborns or infants. Early detection and diagnosis are particularly important. The diagnosis of MMA mainly depends on clinical symptoms, newborn screening, biochemical detection, gene sequencing and neuroimaging diagnosis. The accumulation of methylmalonic acid and other metabolites in the body of patients causes brain tissue damage, which can manifest as various degrees of intellectual disability and severe neurological dysfunction. Neuroimaging examination has important clinical significance in the diagnosis and prognosis of MMA. This review mainly reviews the etiology, pathogenesis, and nervous system development, especially the neuroimaging features of MMA.
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Affiliation(s)
- Tao Chen
- Department of Clinical Laboratory, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Yian Gao
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Shengdong Zhang
- Department of Radiology, Shandong Yinan People’s Hospital, Linyi, Shandong, China
| | - Yuanyuan Wang
- Department of Radiology, Binzhou Medical University, Yantai, Shandong, China
| | - Chaofan Sui
- Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Linfeng Yang
- Department of Radiology, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China,*Correspondence: Linfeng Yang,
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Chapman KA, MacEachern D, Cox GF, Waller M, Fogarty J, Granger S, Stepanians M, Waisbren S. Neuropsychological endpoints for clinical trials in methylmalonic acidemia and propionic acidemia: A pilot study. Mol Genet Metab Rep 2023; 34:100953. [PMID: 36659999 PMCID: PMC9842695 DOI: 10.1016/j.ymgmr.2022.100953] [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: 10/02/2022] [Revised: 12/27/2022] [Accepted: 12/28/2022] [Indexed: 01/09/2023] Open
Abstract
Introduction This pilot study assessed instruments measuring relatively discrete neuropsychological domains to inform the selection of clinical outcome assessments that may be considered for interventional trials in methylmalonic acidemia (MMA) and propionic acidemia (PA). Methods Tests and questionnaires were selected for their possible relevance to MMA and PA and potential sensitivity to modest changes in functioning and behavior. Results Twenty-one patients (<18 years, n = 10;>18 years, n = 11) and/or their caregivers responded to video interviews and paper tests. Language deficits and significant motor deficits in some participants impacted scoring, especially in the verbal and processing speed sections of the Wechsler Intelligence Scale for Children, Fifth Edition (WISC-V) and the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV). However, all participants ≥12 years of age were able to complete the Cookie Theft Picture Task. Thus, verbal discourse remains a potentially useful endpoint for participants in this age group. The Vineland Adaptive Behavior Scales (VABS-3) Adaptive Behavior Composite and Communication Scores confirmed delayed or immature functioning in day-to-day activities in these participants. Significant motor deficits prevented completion of some tests. Computerized processing speed tasks, which require pressing a button or tapping a computer screen, may be easier than writing or checking off boxes on paper in this cohort. Sleep characteristics among MMA participants were within normative ranges of the Child and Adolescent Sleep Checklist (CASC), indicating that this measurement would not provide valuable data in a clinical trial. Despite their challenges, responses to the Metabolic Quality of Life Questionnaire indicated these patients and their caregivers perceive an overall high quality of life. Conclusion Overall, test and questionnaire results were notably different between participants with MMA and participants with PA. The study demonstrates that pilot studies can detect instruments that may not be appropriate for individuals with language or motor deficits and that may not provide a broad range of scores reflecting disease severity. It also provides a rationale for focusing on discrete neuropsychological domains since some aspects of functioning were less affected than others and some were more closely related to disease severity. When global measures are used, overall scores may mask specific deficits. A pilot study like this one cannot ensure that scores will change over time in response to a specific treatment in a clinical trial. However, it can avert the selection of instruments that do not show associations with severity or biomedical parameters likely to be the target of a clinical trial. A pilot study can also identify when differences in diagnoses and baseline functioning need to be addressed prior to developing the analytical plan for the trial.
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Affiliation(s)
- Kimberly A. Chapman
- Children's National Rare Disease Institute, 7125 13th Pl NW, Washington DC 20012, USA,Corresponding author at: 7125 13th Place NW, Washington DC 20012, USA.
| | - Devon MacEachern
- PROMETRIKA, LLC, 100 CambridgePark Drive, Cambridge, MA 02140, USA
| | - Gerald F. Cox
- HemoShear Therapeutics Inc., 501 Locust Ave #301, Charlottesville, VA 22902, USA,Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave., Boston, MA 02115, USA
| | - Mavis Waller
- HemoShear Therapeutics Inc., 501 Locust Ave #301, Charlottesville, VA 22902, USA
| | - Jeanine Fogarty
- HemoShear Therapeutics Inc., 501 Locust Ave #301, Charlottesville, VA 22902, USA
| | - Suzanne Granger
- PROMETRIKA, LLC, 100 CambridgePark Drive, Cambridge, MA 02140, USA
| | | | - Susan Waisbren
- Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave., Boston, MA 02115, USA
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