1
|
Akar HT, Yıldız H, Öztürk Z, Karakaya D, Sezer A, Olgaç A. Case presentation: a severe case of cobalamin c deficiency presenting with nephrotic syndrome, malignant hypertension and hemolytic anemia. BMC Nephrol 2024; 25:217. [PMID: 38977946 PMCID: PMC11232354 DOI: 10.1186/s12882-024-03656-1] [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: 10/28/2023] [Accepted: 06/26/2024] [Indexed: 07/10/2024] Open
Abstract
BACKGROUND The etiology of nephrotic syndrome can vary, with underlying metabolic diseases being a potential factor. Cobalamin C (cblC) defect is an autosomal recessive inborn error of metabolism caused by mutations in the MMACHC gene, resulting in impaired vitamin B12 processing. While cblC defect typically manifests with hematological and neurological symptoms, renal involvement is increasingly recognized but remains rare. CASE PRESENTATION We describe a 7-month-old male patient presenting with fatigue and edema. His first laboratory findings showed anemia, thrombocytopenia, hypoalbuminemia and proteinuria and further examinations reveals hemolysis in peripheric blood smear. During his follow up respiratory distress due to pleural effusion in the right hemithorax was noticed. And fluid leakage to the third spaces supported nephrotic syndrome diagnosis. The patient's condition deteriorated, leading to intensive care admission due to, hypertensive crisis, and respiratory distress. High total plasma homocysteine and low methionine levels raised suspicion of cobalamin metabolism disorders. Genetic testing confirmed biallelic MMACHC gene mutations, establishing the diagnosis of cblC defect. Treatment with hydroxycobalamin, folic acid, and betaine led to remarkable clinical improvement. DISCUSSION/CONCLUSION This case underscores the significance of recognizing metabolic disorders like cblC defect in atypical presentations of nephrotic syndrome. Early diagnosis and comprehensive management are vital to prevent irreversible renal damage. While cblC defects are more commonly associated with atypical hemolytic uremic syndrome, this case highlights the importance of considering cobalamin defects in the differential diagnosis of nephrotic syndrome, especially when associated with accompanying findings such as hemolysis. Our case, which has one of the highest homocysteine levels reported in the literature, emphasizes this situation again.
Collapse
Affiliation(s)
- Halil Tuna Akar
- Department of Pediatric Metabolism, Ankara Etlik City Hospital Health Complex Children's Hospital, Ankara, Turkey.
| | - Harun Yıldız
- Department of Pediatric Metabolism, Ankara Etlik City Hospital Health Complex Children's Hospital, Ankara, Turkey
| | - Zeynelabidin Öztürk
- Department of Pediatric Intensive Care Medicine, Ankara Etlik City Hospital, Ankara, Turkey
| | - Deniz Karakaya
- Department of Pediatric Nephrology, Ankara Etlik City Hospital, Ankara, Turkey
| | - Abdullah Sezer
- Deparment of Medical Genetics, Ankara Etlik City Hospital, Ankara, Turkey
| | - Asburçe Olgaç
- Department of Pediatric Metabolism, Ankara Etlik City Hospital Health Complex Children's Hospital, Ankara, Turkey
| |
Collapse
|
2
|
Arhip L, Brox-Torrecilla N, Romero I, Motilla M, Serrano-Moreno C, Miguélez M, Cuerda C. Late-onset methylmalonic acidemia and homocysteinemia (cblC disease): systematic review. Orphanet J Rare Dis 2024; 19:20. [PMID: 38245797 PMCID: PMC10799514 DOI: 10.1186/s13023-024-03021-3] [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: 03/10/2023] [Accepted: 01/11/2024] [Indexed: 01/22/2024] Open
Abstract
INTRODUCTION Combined methylmalonic acidemia and homocystinuria, cblC type is an inborn error of intracellular cobalamin metabolism and the most common one. The age of onset ranges from prenatal to adult. The disease is characterised by an elevation of methylmalonic acid (MMA) and homocysteine and a decreased production of methionine. The aim is to review existing scientific literature of all late onset cblC patients in terms of clinical symptoms, diagnosis, and outcome. METHODS A bibliographic database search was undertaken in PubMed (MEDLINE) complemented by a reference list search. We combined search terms regarding cblC disease and late onset. Two review authors performed the study selection, data extraction and quality assessment. RESULTS Of the sixty-five articles included in this systematic review, we collected a total of 199 patients. The most frequent clinical symptoms were neuropathy/myelopathy, encephalopathy, psychiatric symptoms, thrombotic microangiopathy, seizures, kidney disease, mild to severe pulmonary hypertension with heart failure and thrombotic phenomena. There were different forms of supplementation used in the different studies collected and, within these studies, some patients received several treatments sequentially and/or concomitantly. The general outcome was: 64 patients recovered, 78 patients improved, 4 patients did not improve, or the disease progressed, and 12 patients died. CONCLUSIONS Most scientific literature regarding the late onset cblC disease comes from case reports and case series. In most cases treatment initiation led to an improvement and even recovery of some patients. The lack of complete recovery underlines the necessity for increased vigilance in unclear clinical symptoms for cblC disease.
Collapse
Affiliation(s)
- Loredana Arhip
- Unidad de Nutrición Clínica y Dietética, Hospital General Universitario Gregorio Marañón, Calle del Doctor Esquerdo 46, 28007, Madrid, Spain.
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.
| | | | | | - Marta Motilla
- Unidad de Nutrición Clínica y Dietética, Hospital General Universitario Gregorio Marañón, Calle del Doctor Esquerdo 46, 28007, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Clara Serrano-Moreno
- Unidad de Nutrición Clínica y Dietética, Hospital General Universitario Gregorio Marañón, Calle del Doctor Esquerdo 46, 28007, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - María Miguélez
- Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain
| | - Cristina Cuerda
- Unidad de Nutrición Clínica y Dietética, Hospital General Universitario Gregorio Marañón, Calle del Doctor Esquerdo 46, 28007, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
- Universidad Complutense Madrid, Madrid, Spain
| |
Collapse
|
3
|
Sun M, Dai Y. Late-onset cobalamin C deficiency type in adult with cognitive and behavioral disturbances and significant cortical atrophy and cerebellar damage in the MRI: a case report. Front Neurol 2023; 14:1308289. [PMID: 38148982 PMCID: PMC10749923 DOI: 10.3389/fneur.2023.1308289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 11/21/2023] [Indexed: 12/28/2023] Open
Abstract
Background Late-onset cobalamin C (cblC) deficiency is associated with a wide range of neurological and psychiatric symptoms, hematological manifestations, anorexia, renal failure, ocular abnormalities, dermatitis, and pancreatitis. However, the neuroimaging characteristics of late-onset cblC deficiency remain insufficiently documented. Common findings include diffuse white matter swelling, varying degrees of severe leukoaraiosis, hydrocephalus, corpus callosum atrophy, and symmetric bilateral basal ganglia lesions. In this report, we present a case of late-onset cblC deficiency in adults presenting with cerebellar ataxia as the primary symptom. The MRI findings revealed bilateral lateral cerebellar hemispheres exhibiting symmetric hyperintensity, primarily observed in diffusion-weighted imaging (DWI), which is a rarely reported imaging change in this context. Case presentation Our patient was a male who experienced symptoms starting at the age of 30 years, including unsteady walking, apparent cerebellar ataxia, and cognitive impairment upon nervous system examination. Brain magnetic resonance imaging (MRI) exhibited symmetric hyperintensity in the bilateral lateral cerebellar hemispheres, predominantly manifested in DWI, without any enhancement. Subsequently, significantly elevated blood total homocysteine and urinary methylmalonic acid levels were observed. Genetic analysis confirmed the presence of MMACHC compound heterozygous mutants c.482G > A and c.609G > A, thus confirming the diagnosis of cblC deficiency. These variants were classified as likely pathogenic following the guidelines of the American College of Medical Genetics and Genomics (ACMG) and were verified using Sanger sequencing. Following treatment, the patient experienced improvements in walking ability and cognition, a significant decrease in blood total homocysteine levels, and reversal of the imaging lesions. In conclusion Late-onset cblC deficiency presents with diverse clinical and imaging manifestations. Early diagnosis and treatment are crucial in achieving a favorable prognosis. This case serves as a reminder to clinicians not to overlook genetic metabolic disorders, particularly those causing multisite damage, in adult patients with undiagnosed neurological disorders, especially those affecting the cerebellum. Notably, methylmalonic acidemia should be considered within the spectrum of bilateral cerebellar lesions.
Collapse
Affiliation(s)
| | - Yingjie Dai
- Department of Neurology, General Hospital of Northern Theater Command, Shenyang, China
| |
Collapse
|
4
|
Differences in the Formation of Reactive Oxygen Species and Their Cytotoxicity between Thiols Combined with Aqua- and Cyanocobalamins. Int J Mol Sci 2022; 23:ijms231911032. [PMID: 36232333 PMCID: PMC9569724 DOI: 10.3390/ijms231911032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/09/2022] [Accepted: 09/15/2022] [Indexed: 11/23/2022] Open
Abstract
Cobalamin is an essential nutrient required for the normal functioning of cells. Its deficiency can lead to various pathological states. Hydroxocobalamin (HOCbl) and cyanocobalamin (CNCbl) are the forms of vitamin B12 that are most commonly used for supplementation. There is substantial evidence indicating that cobalamins can both suppress and promote oxidative stress; however, the mechanisms underlying these effects are poorly understood. Here, it was shown that the oxidation of thiols catalyzed by HOCbl and CNCbl is accompanied by reactive oxygen species (ROS) production and induces, under certain conditions, oxidative stress and cell death. The form of vitamin B12 and the structure of thiol play a decisive role in these processes. It was found that the mechanisms and kinetics of thiol oxidation catalyzed by HOCbl and CNCbl differ substantially. HOCbl increased the rate of oxidation of thiols to a greater extent than CNCbl, but quenched ROS in combination with certain thiols. Oxidation catalyzed by CNCbl was generally slower. Yet, the absence of ROS quenching resulted in their higher accumulation. The aforementioned results might explain a more pronounced cytotoxicity induced by combinations of thiols with CNCbl. On the whole, the data obtained provide a new insight into the redox processes in which cobalamins are involved. Our results might also be helpful in developing new approaches to the treatment of some cobalamin-responsive disorders in which oxidative stress is an important component.
Collapse
|
5
|
Wiedemann A, Oussalah A, Lamireau N, Théron M, Julien M, Mergnac JP, Augay B, Deniaud P, Alix T, Frayssinoux M, Feillet F, Guéant JL. Clinical, phenotypic and genetic landscape of case reports with genetically proven inherited disorders of vitamin B 12 metabolism: A meta-analysis. Cell Rep Med 2022; 3:100670. [PMID: 35764087 PMCID: PMC9381384 DOI: 10.1016/j.xcrm.2022.100670] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 11/22/2021] [Accepted: 06/02/2022] [Indexed: 10/31/2022]
Abstract
Inherited disorders of B12 metabolism produce a broad spectrum of manifestations, with limited knowledge of the influence of age and the function of related genes. We report a meta-analysis on 824 patients with a genetically proven diagnosis of an inherited disorder of vitamin B12 metabolism. Gene clusters and age categories are associated with patients' manifestations. The "cytoplasmic transport" cluster is associated with neurological and ophthalmological manifestations, the "mitochondrion" cluster with hypotonia, acute metabolic decompensation, and death, and the "B12 availability" and "remethylation" clusters with anemia and cytopenia. Hypotonia, EEG abnormalities, nystagmus, and strabismus are predominant in the younger patients, while neurological manifestations, such as walking difficulties, peripheral neuropathy, pyramidal syndrome, cerebral atrophy, psychiatric disorders, and thromboembolic manifestations, are predominant in the older patients. These results should prompt systematic checking of markers of vitamin B12 status, including homocysteine and methylmalonic acid, when usual causes of these manifestations are discarded in adult patients.
Collapse
Affiliation(s)
- Arnaud Wiedemann
- Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM UMR_S 1256, 54000 Nancy, France; Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France; Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000 Nancy, France
| | - Abderrahim Oussalah
- Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM UMR_S 1256, 54000 Nancy, France; Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000 Nancy, France; Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France
| | - Nathalie Lamireau
- Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France
| | - Maurane Théron
- Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France
| | - Melissa Julien
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France
| | | | - Baptiste Augay
- Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France
| | - Pauline Deniaud
- Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France
| | - Tom Alix
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France
| | - Marine Frayssinoux
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France
| | - François Feillet
- Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM UMR_S 1256, 54000 Nancy, France; Department of Pediatrics, University Hospital of Nancy, 54000 Nancy, France; Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000 Nancy, France
| | - Jean-Louis Guéant
- Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, INSERM UMR_S 1256, 54000 Nancy, France; Reference Center for Inborn Errors of Metabolism (ORPHA67872), University Hospital of Nancy, 54000 Nancy, France; Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, Nutrition, and Metabolism, University Hospital of Nancy, 54000 Nancy, France.
| |
Collapse
|
6
|
Kalantari S, Brezzi B, Bracciamà V, Barreca A, Nozza P, Vaisitti T, Amoroso A, Deaglio S, Manganaro M, Porta F, Spada M. Adult-onset CblC deficiency: a challenging diagnosis involving different adult clinical specialists. Orphanet J Rare Dis 2022; 17:33. [PMID: 35109910 PMCID: PMC8812048 DOI: 10.1186/s13023-022-02179-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/16/2022] [Indexed: 12/13/2022] Open
Abstract
Background Methylmalonic aciduria and homocystinuria, CblC type (OMIM #277400) is the most common disorder of cobalamin intracellular metabolism, an autosomal recessive disease, whose biochemical hallmarks are hyperhomocysteinemia, methylmalonic aciduria and low plasma methionine. Despite being a well-recognized disease for pediatricians, there is scarce awareness of its adult presentation. A thorough analysis and discussion of cobalamin C defect presentation in adult patients has never been extensively performed. This article reviews the published data and adds a new case of the latest onset of symptoms ever described for the disease.
Results We present the emblematic case of a 45-year-old male, describing the diagnostic odyssey he ventured through to get to the appropriate treatment and molecular diagnosis. Furthermore, available clinical, biochemical and molecular data from 22 reports on cases and case series were collected, resulting in 45 adult-onset CblC cases, including our own. We describe the onset of the disease in adulthood, encompassing neurological, psychiatric, renal, ophthalmic and thromboembolic symptoms. In all cases treatment with intramuscular hydroxycobalamin was effective in reversing symptoms. From a molecular point of view adult patients are usually compound heterozygous carriers of a truncating and a non-truncating variant in the MMACHC gene. Conclusion Adult onset CblC disease is a rare disorder whose diagnosis can be delayed due to poor awareness regarding its presenting insidious symptoms and biochemical hallmarks. To avoid misdiagnosis, we suggest that adult onset CblC deficiency is acknowledged as a separate entity from pediatric late onset cases, and that the disease is considered in the differential diagnosis in adult patients with atypical hemolytic uremic syndromes and/or slow unexplained decline in renal function and/or idiopathic neuropathies, spinal cord degenerations, ataxias and/or recurrent thrombosis and/or visual field defects, maculopathy and optic disc atrophy. Plasma homocysteine measurement should be the first line for differential diagnosis when the disease is suspected. To further aid diagnosis, it is important that genes belonging to the intracellular cobalamin pathway are included within gene panels routinely tested for atypical hemolytic uremic syndrome and chronic kidney disorders. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02179-y.
Collapse
Affiliation(s)
- Silvia Kalantari
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Brigida Brezzi
- Nephrology and Dialysis Unit, Azienda Ospedaliera "SS. Antonio e Biagio e Cesare Arrigo", Alessandria, Italy
| | | | - Antonella Barreca
- Anatomia e Istologia Patologica, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - Paolo Nozza
- S.C. Anatomia e Istologia Patologica, Azienda Ospedaliera "SS. Antonio e Biagio e Cesare Arrigo", Alessandria, Italy
| | - Tiziana Vaisitti
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Antonio Amoroso
- Department of Medical Sciences, University of Turin, Turin, Italy.,Immunogenetics and Biology of Transplantation, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - Silvia Deaglio
- Department of Medical Sciences, University of Turin, Turin, Italy.,Immunogenetics and Biology of Transplantation, Città della Salute e della Scienza University Hospital, Turin, Italy
| | - Marco Manganaro
- Nephrology and Dialysis Unit, Azienda Ospedaliera "SS. Antonio e Biagio e Cesare Arrigo", Alessandria, Italy
| | - Francesco Porta
- Department of Pediatrics, Città della Salute e della Scienza University Hospital, University of Torino, Piazza Polonia 94, 10126, Turin, Italy.
| | - Marco Spada
- Department of Pediatrics, Città della Salute e della Scienza University Hospital, University of Torino, Piazza Polonia 94, 10126, Turin, Italy
| |
Collapse
|
7
|
Matmat K, Guéant-Rodriguez RM, Oussalah A, Wiedemann-Fodé A, Dionisi-Vici C, Coelho D, Guéant JL, Conart JB. Ocular manifestations in patients with inborn errors of intracellular cobalamin metabolism: a systematic review. Hum Genet 2021; 141:1239-1251. [PMID: 34652574 DOI: 10.1007/s00439-021-02350-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 08/19/2021] [Indexed: 01/26/2023]
Abstract
Inherited disorders of cobalamin (cbl) metabolism (cblA-J) result in accumulation of methylmalonic acid (MMA) and/or homocystinuria (HCU). Clinical presentation includes ophthalmological manifestations related to retina, optic nerve and posterior visual alterations, mainly reported in cblC and sporadically in other cbl inborn errors.We searched MEDLINE EMBASE and Cochrane Library, and analyzed articles reporting ocular manifestations in cbl inborn errors. Out of 166 studies a total of 52 studies reporting 163 cbl and 24 mut cases were included. Ocular manifestations were found in all cbl defects except for cblB and cblD-MMA; cblC was the most frequent disorder affecting 137 (84.0%) patients. The c.271dupA was the most common pathogenic variant, accounting for 70/105 (66.7%) cases. One hundred and thirty-seven out of 154 (88.9%) patients presented with early-onset disease (0-12 months). Nystagmus and strabismus were observed in all groups with the exception of MMA patients while maculopathy and peripheral retinal degeneration were almost exclusively found in MMA-HCU patients. Optic nerve damage ranging from mild temporal disc pallor to complete atrophy was prevalent in MMA-HCU.and MMA groups. Nystagmus was frequent in early-onset patients. Retinal and macular degeneration worsened despite early treatment and stabilized systemic function in these patients. The functional prognosis remains poor with final visual acuity < 20/200 in 55.6% (25/45) of cases. In conclusion, the spectrum of eye disease in Cbl patients depends on metabolic severity and age of onset. The development of visual manifestations over time despite early metabolic treatment point out the need for specific innovative therapies.
Collapse
Affiliation(s)
- Karim Matmat
- UMR_S 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, INSERM, University of Lorraine, 54000, Nancy, France
| | - Rosa-Maria Guéant-Rodriguez
- UMR_S 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, INSERM, University of Lorraine, 54000, Nancy, France.
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, 54000, Nancy, France.
| | - Abderrahim Oussalah
- UMR_S 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, INSERM, University of Lorraine, 54000, Nancy, France
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, 54000, Nancy, France
| | - Arnaud Wiedemann-Fodé
- UMR_S 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, INSERM, University of Lorraine, 54000, Nancy, France
| | - Carlo Dionisi-Vici
- Division of Metabolism, Bambino Gesù Children's Hospital IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy
| | - David Coelho
- UMR_S 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, INSERM, University of Lorraine, 54000, Nancy, France
| | - Jean-Louis Guéant
- UMR_S 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, INSERM, University of Lorraine, 54000, Nancy, France
- National Center of Inborn Errors of Metabolism, University Regional Hospital Center of Nancy, 54000, Nancy, France
| | - Jean-Baptiste Conart
- UMR_S 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, INSERM, University of Lorraine, 54000, Nancy, France.
- Department of Ophthalmology, Nancy University Hospital, 54500, Vandœuvre-lès-Nancy, France.
| |
Collapse
|
8
|
Wei Y, Hao H. Late-onset cobalamin C disease presenting with acute cerebellar ataxia. Neurol Sci 2021; 42:4839-4842. [PMID: 34392393 DOI: 10.1007/s10072-021-05541-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/31/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Yanping Wei
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing Shuaifuyuan 1, Dongcheng District, Beijing, 100730, People's Republic of China
| | - Honglin Hao
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing Shuaifuyuan 1, Dongcheng District, Beijing, 100730, People's Republic of China.
| |
Collapse
|
9
|
Zhao QH, Wu WH, Fu LJ, Wang L. Adult-onset hypoxaemia, diffuse lung lesions, and pulmonary hypertension in cobalamin C defect: a case report. Eur Heart J Case Rep 2021; 5:ytab251. [PMID: 34222785 PMCID: PMC8243222 DOI: 10.1093/ehjcr/ytab251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 06/14/2021] [Indexed: 11/14/2022]
Abstract
BACKGROUND Cobalamin C (cbl-C) defect is an inherited autosomal recessive disorder that commonly affects the central nervous system of infants. Severe pulmonary hypertension (PH) and diffuse lung lesions are unusual clinical manifestations, especially among adults. CASE SUMMARY A 25-year-old man with hypoxaemia, diffuse lung lesions, and PH, suddenly developed nausea, vomiting, headache, and worsening of dyspnoea. Metabolic screening showed elevated serum levels of methylmalonic acid and homocysteine, and genetic testing revealed MMACHC gene mutations. He was eventually diagnosed with severe PH secondary to cbl-C defect and was successfully managed with vitamin B12, betaine, L-carnitine, folate, as well as ambrisentan and sildenafil. DISCUSSION cbl-C is a rare cause of PH and can present with severe PH and diffuse lung lesions in adults. Given that the condition is treatable, a careful metabolic screening should be considered when a diagnosis of PH is made.
Collapse
Affiliation(s)
- Qin-Hua Zhao
- Department of Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507, Zhengmin Road, Shanghai 200433, China
| | - Wen-Hui Wu
- Department of Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507, Zhengmin Road, Shanghai 200433, China
| | - Li-Jun Fu
- Department of Cardiology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, 1678, Dongfang Road, Shanghai 200127, China
| | - Lan Wang
- Department of Pulmonary Circulation, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507, Zhengmin Road, Shanghai 200433, China
| |
Collapse
|
10
|
Chen T, Liang L, Zhang H, Ye J, Qiu W, Xiao B, Zhu H, Wang L, Xu F, Gong Z, Gu X, Han L. Value of amniotic fluid homocysteine assay in prenatal diagnosis of combined methylmalonic acidemia and homocystinuria, cobalamin C type. Orphanet J Rare Dis 2021; 16:125. [PMID: 33691766 PMCID: PMC7945211 DOI: 10.1186/s13023-021-01762-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/25/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Combined methylmalonic acidemia and homocystinuria, cobalamin C type (cblC defect) is the most common inborn error of cobalamin metabolism, and different approaches have been applied to its prenatal diagnosis. To evaluate the reliability of biochemical method for the prenatal diagnosis of cblC defect, we conducted a retrospective study of our 10-year experience at a single center. METHODS 248 pregnancies whose probands were diagnosed as cblC defect were referred to our center for prenatal diagnosis from January 2010 to December 2019. Prenatal data of Hcy levels determined by enzymatic cycling assay, acylcarnitine analysis using liquid chromatography tandem mass spectrometry, organic acid analysis using gas chromatography mass spectrometry, and genetic analysis by direct sequencing of 248 at-risk fetuses were retrospectively reviewed. RESULTS For 2.0 and 16.0 μmol/L levels of Hcy AF samples, the relative errors were - 2.5% and 2.8%, respectively. The respective measurement uncertainties were 13.07% and 14.20%. For the 248 at-risk fetuses, 63 fetuses were affected and 185 fetuses were unaffected. Hcy level of 13.20 (6.62-43.30) μmol/L in 63 affected fetuses was significantly higher than that in 185 unaffected fetuses of 2.70 (0.00-5.80) μmol/L, and there was no overlap between the affected and unaffected groups. The diagnostic sensitivity and specificity of Hcy were 100% and 92.05%, respectively. The positive and negative predictive values of the combination of Hcy, propionylcarnitine (C3), ratio of C3 to acetylcarnitine (C2; C3/C2), methylmalonic acid (MMA), and methylcitric acid (MCA) were both 100%. Sixteen fetuses displayed inconclusive genetic results of MMACHC variants, in which seven fetuses were determined to be affected with elevated levels of Hcy, C3, C3/C2 and MMA, and their levels were 18.50 (6.70-43.30) μmol/L, 8.53(5.02-11.91) μmol/L, 0.77 (0.52-0.97), 8.96 (6.55-40.32) mmol/mol Cr, respectively. The remaining nine fetuses were considered unaffected based on a normal amniotic fluid metabolite profile. CONCLUSIONS Hcy appears to be another characteristic biomarker for the prenatal diagnosis of cblC defect. The combination of Hcy assay with acylcarnitine and organic acid analysis is a fast, sensitive, and reliable prenatal diagnostic biochemical approach. This approach could overcome the challenge of the lack of genetic analysis for families with at-risk cblC defect fetuses.
Collapse
Affiliation(s)
- Ting Chen
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Lili Liang
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Huiwen Zhang
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Jun Ye
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Wenjuan Qiu
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Bing Xiao
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Hong Zhu
- Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Lei Wang
- Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Feng Xu
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Zhuwen Gong
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Xuefan Gu
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China.,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China
| | - Lianshu Han
- Department of Pediatric Endocrinology and Genetic, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Yangpu District, Shanghai, 200092, China. .,Center for Prenatal Diagnosis, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
| |
Collapse
|
11
|
Kaur R, Attri SV, Saini AG, Sankhyan N. A high frequency and geographical distribution of MMACHC R132* mutation in children with cobalamin C defect. Amino Acids 2021; 53:253-264. [PMID: 33515116 DOI: 10.1007/s00726-021-02942-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 12/19/2020] [Indexed: 12/16/2022]
Abstract
Cobalamin C defect is caused by pathogenic variants in the MMACHC gene leading to impaired conversion of dietary vitamin B12 into methylcobalamin and adenosylcobalamin. Variants in the MMACHC gene cause accumulation of methylmalonic acid and homocysteine along with decreased methionine synthesis. The spectrum of MMACHC gene variants differs in various populations. A total of 19 North Indian children (age 0-18 years) with elevated methylmalonic acid and homocysteine were included in the study, and their DNA samples were subjected to Sanger sequencing of coding exons with flanking intronic regions of MMACHC gene. The genetic analysis resulted in the identification of a common pathogenic nonsense mutation, c.394C > T (R132*) in 85.7% of the unrelated cases with suspected cobalamin C defect. Two other known mutations c.347T > C (7%) and c.316G > A were also detected. Plasma homocysteine was significantly elevated (> 100 µmol/L) in 75% of the cases and methionine was decreased in 81% of the cases. Propionyl (C3)-carnitine, the primary marker for cobalamin C defect, was found to be elevated in only 43.75% of cases. However, the secondary markers such as C3/C2 and C3/C16 ratios were elevated in 87.5% and 100% of the cases, respectively. Neurological manifestations were the most common in our cohort. Our findings of the high frequency of a single MMACHC R132* mutation in cases with combined homocystinuria and methylmalonic aciduria may be proven helpful in designing a cost-effective and time-saving diagnostic strategy for resource-constraint settings. Since the R132* mutation is located near the last exon-exon junction, this is a potential target for the read-through therapeutics.
Collapse
Affiliation(s)
- Rajdeep Kaur
- Pediatric Biochemistry Unit, Department of Pediatrics, PGIMER, Chandigarh, 160012, India
| | - Savita Verma Attri
- Pediatric Biochemistry Unit, Department of Pediatrics, PGIMER, Chandigarh, 160012, India.
| | - Arushi Gahlot Saini
- Pediatric Neurology Unit, Department of Pediatrics, PGIMER, Chandigarh, India
| | - Naveen Sankhyan
- Pediatric Neurology Unit, Department of Pediatrics, PGIMER, Chandigarh, India
| |
Collapse
|
12
|
Padma Srivastava MV, Agarwal A, Upadhyay V, Gupta A, Garg A, Vishnu V, Rajan R, Singh M, Bhatia R. Cobalamin c disease: Cognitive dysfunction, spastic ataxic paraparesis, and cerebral white matter hyperintensities in a genetic but easily treatable cause! Ann Indian Acad Neurol 2021; 24:997-999. [PMID: 35359513 PMCID: PMC8965946 DOI: 10.4103/aian.aian_729_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/10/2020] [Accepted: 07/29/2020] [Indexed: 11/04/2022] Open
|
13
|
Abstract
Introduction Introduction: cobalamin C (Cbl C) deficiency is the most common defect in intracellular cobalamin metabolism, associated with methylmalonic acidemia and homocystinuria. Its late clinical presentation is heterogeneous and may lead to a diagnostic delay. Case report: we report the case of a 45-year-old man with a 20-year history of chronic kidney disease and recently diagnosed spastic paraparesis, both of unknown origin. Metabolic studies revealed elevated levels of homocysteine and methylmalonic acid in the blood and urine. A genetic study confirmed cobalamin C deficiency. Treatment with hydroxocobalamin, betaine, carnitine, and folic acid was started. The patient eventually received a kidney transplant. Discussion: early diagnosis and appropriate treatment improve the clinical evolution of patients with Cbl C deficiency. Determination of homocysteine, organic acids, and other amino acids should be included in the differential diagnosis of patients with nephrological-neurological symptoms without a clear etiology.
Collapse
|
14
|
Chu X, Meng L, Zhang W, Luo J, Wang Z, Yuan Y. Peripheral Nervous System Involvement in Late-Onset Cobalamin C Disease? Front Neurol 2020; 11:594905. [PMID: 33324334 PMCID: PMC7726435 DOI: 10.3389/fneur.2020.594905] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/28/2020] [Indexed: 11/13/2022] Open
Abstract
Background: Cobalamin C (cblC) has a fundamental role in both central and peripheral nervous system function at any age. Neurologic manifestations may be the earliest and often the only manifestation of hereditary or acquired cblC defect. Peripheral neuropathy remains a classical but underdiagnosed complication of cblC defect, especially in late-onset cblC disease caused by mutations in the methylmalonic aciduria type C and homocysteinemia (MMACHC) gene. So the clinical, electrophysiological, and pathological characteristics of late-onset cblC disease are not well-known. Methods: A retrospective study of patients with late-onset cblC disease was conducted at our hospital on a 3-year period. The neuropathy was confirmed by the nerve conduction study. Sural biopsies were performed in 2 patients. Results: Eight patients were identified, with a mean onset age of 16.25 ± 6.07 years. All patients had methylmalonic aciduria, homocysteinemia, compound heterozygous MMACHC gene mutations were detected in all patients, and 7/8 patients with c.482G>A mutation. One patient concomitant with homozygote c.665C>T mutation in 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. All patients showed limb weakness and cognitive impairment. Five patients had possible sensorimotor axonal polyneuropathy predominantly in the distal lower limbs. Sural biopsies showed loss of myelinated and unmyelinated fibers. Electro microscopy revealed crystalline-like inclusions bodies in Schwann cells and axonal degeneration. Conclusion: Late-onset cblC disease had possible heterogeneous group of distal axonal neuropathy. c.482G>A mutation is a hot spot mutation in late-onset cblC disease.
Collapse
Affiliation(s)
- Xujun Chu
- Department of Neurology, First Hospital, Peking University, Beijing, China
| | - Lingchao Meng
- Department of Neurology, First Hospital, Peking University, Beijing, China
| | - Wei Zhang
- Department of Neurology, First Hospital, Peking University, Beijing, China
| | - Jinjun Luo
- Department of Neurology, Temple University, Philadelphia, PA, United States
| | - Zhaoxia Wang
- Department of Neurology, First Hospital, Peking University, Beijing, China
| | - Yun Yuan
- Department of Neurology, First Hospital, Peking University, Beijing, China
| |
Collapse
|
15
|
Chang KJ, Zhao Z, Shen HR, Bing Q, Li N, Guo X, Hu J. Adolescent/adult-onset homocysteine remethylation disorders characterized by gait disturbance with/without psychiatric symptoms and cognitive decline: a series of seven cases. Neurol Sci 2020; 42:1987-1993. [PMID: 33000330 DOI: 10.1007/s10072-020-04756-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 09/23/2020] [Indexed: 12/11/2022]
Abstract
Homocysteine remethylation disorders are rare inherited disorders caused by a deficient activity of the enzymes involved in the remethylation of homocysteine to methionine. The adolescent/adult-onset remethylation disorders are rarely reported. We analyzed the clinical and genetic characteristics of seven cases with adolescent/adult remethylation disorders, including 5 cases of the cobalamin C disease (cblC) and 2 cases of the methylenetetrahydrofolate reductase deficiency. The average onset age was 21.1 (range 14 to 40) years. All patients complained of gait disturbances. Other common symptoms included psychiatric symptoms (5/7) and cognitive decline (4/7). Acute encephalopathy, dysarthria, anorexia, vomiting, ketoacidosis, anemia, cataract, and hand tremor were also observed. The mean total homocysteine in serum when the patients were diagnosed was 94.6 (range 53.1-154.5) mol/L. Electrophysiological studies revealed neuropathy in the lower limbs (6/7). The brain MRI showed reversible altered signal from the dorsal portions of the cerebellar hemispheres (1/7), periventricular hyperintensity (2/7), and delayed/impaired myelination (2/7). The sural nerve biopsy performed in one case showed a modest loss of myelinated fibers. Five patients showed heterozygous mutations of the MMACHC gene, including c.482G>A (5/5), c.609G>A (2/5), and c.658-660delAAG (3/5). Two patients showed heterozygous mutations of the MTHFR gene, including c.698C>A (2/2), c.698C>G (1/2), and c.236+1G>A (1/2). The patients responded well to the treatments with significant improvements. Adolescent/adult-onset remethylation disorders are easily misdiagnosed. We recommend testing the serum homocysteine concentrations in young/adult patients with unexplained neuro-psychotic symptoms. Furthermore, individuals with significantly elevated serum homocysteine concentrations should be further tested by organic acid screening and genetic analysis.
Collapse
Affiliation(s)
- Kai-Jie Chang
- Department of Neuromuscular Disorders, The Third Hospital of Hebei Medical University, No 139 Road Ziqiang, Shijiazhuang, 050051, People's Republic of China
| | - Zhe Zhao
- Department of Neuromuscular Disorders, The Third Hospital of Hebei Medical University, No 139 Road Ziqiang, Shijiazhuang, 050051, People's Republic of China
| | - Hong-Rui Shen
- Department of Neuromuscular Disorders, The Third Hospital of Hebei Medical University, No 139 Road Ziqiang, Shijiazhuang, 050051, People's Republic of China
| | - Qi Bing
- Department of Neuromuscular Disorders, The Third Hospital of Hebei Medical University, No 139 Road Ziqiang, Shijiazhuang, 050051, People's Republic of China
| | - Nan Li
- Department of Neuromuscular Disorders, The Third Hospital of Hebei Medical University, No 139 Road Ziqiang, Shijiazhuang, 050051, People's Republic of China
| | - Xuan Guo
- Department of Neuromuscular Disorders, The Third Hospital of Hebei Medical University, No 139 Road Ziqiang, Shijiazhuang, 050051, People's Republic of China
| | - Jing Hu
- Department of Neuromuscular Disorders, The Third Hospital of Hebei Medical University, No 139 Road Ziqiang, Shijiazhuang, 050051, People's Republic of China.
| |
Collapse
|
16
|
Wei Y, Guan Y, Hao H. Late-onset cobalamin C disease presenting with acute progressive polyneuropathy. Muscle Nerve 2020; 61:E37-E40. [PMID: 32208535 DOI: 10.1002/mus.26865] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 03/10/2020] [Accepted: 03/16/2020] [Indexed: 01/06/2023]
Affiliation(s)
- Yanping Wei
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yuzhou Guan
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Honglin Hao
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| |
Collapse
|
17
|
Higashimoto T, Kim AY, Ogawa JT, Sloan JL, Almuqbil MA, Carlson JM, Manoli I, Venditti CP, Gunay-Aygun M, Wang T. High-dose hydroxocobalamin achieves biochemical correction and improvement of neuropsychiatric deficits in adults with late onset cobalamin C deficiency. JIMD Rep 2019; 51:17-24. [PMID: 32071835 PMCID: PMC7012733 DOI: 10.1002/jmd2.12087] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 10/24/2019] [Accepted: 11/14/2019] [Indexed: 12/18/2022] Open
Abstract
Cobalamin C (cblC) deficiency is the most common inborn error of intracellular cobalamin metabolism caused by pathogenic variant(s) in MMACHC and manifests with methylmalonic acidemia, hyperhomocysteinemia, and hypomethioninemia with a variable age of presentation. Individuals with late‐onset cblC may be asymptomatic until manifesting neuropsychiatric symptoms, thromboembolic events, and renal disease. Although hydroxocobalamin provides a foundation for therapy, optimal dose regimen for adult patients has not been systematically evaluated. We report three adult siblings with late‐onset cblC disease, and their biochemical and clinical responses to high‐dose hydroxocobalamin. The 28‐year‐old proband presented with severe psychosis, progressive neurological deterioration, and deep venous thrombosis complicated by a pulmonary embolism. MRI studies identified lesions in the spinal cord, periventricular white matter, and basal ganglia. Serum homocysteine and methylmalonic acid levels were markedly elevated. Hydroxocobalamin at standard dose (1 mg/day) initially resulted in partial metabolic correction. A regimen of high‐dose hydroxocobalamin (25 mg/day) together with betaine and folic acid resulted in rapid and sustainable biochemical correction, resolution of psychosis, improvement of neurological functions, and amelioration of brain and spinal cord lesions. Two siblings who did not manifest neuropsychiatric symptoms or thromboembolism achieved a satisfactory metabolic control with the same high‐dose regimen. Hydroxocobalamin injection was then spaced out to 25 mg weekly with good and sustainable metabolic control. All three patients are compound heterozygotes for c.271dupA p.Arg91LysfsX14 and c.389A > G p.Tyr130Cys. This study highlights the importance of evaluating intracellular cobalamin metabolism in adults with neuropsychiatric manifestations and/or thromboembolic events, and demonstrates that high‐dose hydroxocobalamin achieves rapid and sustainable metabolic control and improvement in neuropsychiatric outcomes in adults with late‐onset cblC disease.
Collapse
Affiliation(s)
- Tomoyasu Higashimoto
- Department of Genetic Medicine and Pediatrics Johns Hopkins University Baltimore Maryland
| | - Alexander Y Kim
- Department of Genetic Medicine and Pediatrics Johns Hopkins University Baltimore Maryland
| | - Jessica T Ogawa
- Department of Genetic Medicine and Pediatrics Johns Hopkins University Baltimore Maryland
| | - Jennifer L Sloan
- Medical Genomics and Metabolic Genetics Branch National Institute of Human Genome Research, National Institutes of Health Bethesda Maryland
| | - Mohammed A Almuqbil
- Department of Genetic Medicine and Pediatrics Johns Hopkins University Baltimore Maryland.,Division of Pediatric Neurology King Saud bin Abdulaziz University for Health Sciences Riyadh Saudi Arabia.,King Abdullah International Medical Research Center King Abdullah Specialist Children's Hospital - Ministry of National Guard Riyadh Saudi Arabia
| | - Julia M Carlson
- Department of Neurology Johns Hopkins University Baltimore Maryland
| | - Irini Manoli
- Medical Genomics and Metabolic Genetics Branch National Institute of Human Genome Research, National Institutes of Health Bethesda Maryland
| | - Charles P Venditti
- Medical Genomics and Metabolic Genetics Branch National Institute of Human Genome Research, National Institutes of Health Bethesda Maryland
| | - Meral Gunay-Aygun
- Department of Genetic Medicine and Pediatrics Johns Hopkins University Baltimore Maryland
| | - Tao Wang
- Department of Genetic Medicine and Pediatrics Johns Hopkins University Baltimore Maryland
| |
Collapse
|