1.
Mutations in MTHFR and POLG impaired activity of the mitochondrial respiratory chain in 46-year-old twins with spastic paraparesis.
Wiedemann, A, Chery, C, Coelho, D, Flayac, J, Gueguen, N, Desquiret-Dumas, V, Feillet, F, Lavigne, C, Neau, JP, Fowler, B, et al
Journal of human genetics. 2020;(2):91-98
Abstract
Hereditary spastic paraplegias (HSPs) are characterized by lower extremity spasticity and weakness. HSP is often caused by mutations in SPG genes, but it may also be produced by inborn errors of metabolism. We performed next-generation sequencing of 4813 genes in one adult twin pair with HSP and severe muscular weakness occurring at the same age. We found two pathogenic compound heterozygous variants in MTHFR, including a variant not referenced in international databases, c.197C>T (p.Pro66Leu) and a known variant, c.470G>A (p.Arg157Gln), and two heterozygous pathogenic variants in POLG, c.1760C>T (p.Pro587Leu) and c.752C>T (p.Thr251Ile). MTHFR and POLG mutations were consistent with the severe muscle weakness and the metabolic changes, including hyperhomocysteinemia and decreased activity of both N(5,10)methylenetetrahydrofolate reductase (MTHFR) and complexes I and II of the mitochondrial respiratory chain. These data suggest the potential role of MTHFR and POLG mutations through consequences on mitochondrial dysfunction in the occurrence of spastic paraparesis phenotype with combined metabolic, muscular, and neurological components.
2.
Multidisciplinary approach and anesthetic management of a surgical cancer patient with methylene tetrahydrofolate reductase deficiency: a case report and review of the literature.
Cascella, M, Arcamone, M, Morelli, E, Viscardi, D, Russo, V, De Franciscis, S, Belli, A, Accardo, R, Caliendo, D, De Luca, E, et al
Journal of medical case reports. 2015;:175
Abstract
INTRODUCTION Hyperhomocysteinemia is a known risk factor for myocardial infarction, stroke, peripheral vascular disease, and thrombosis. Elevated plasma homocysteine levels have been demonstrated in patients with recurrent episodes or a single episode of thrombosis. Here we describe the development of cardiovascular disease as a complication of a surgical intervention in a patient with colorectal cancer and hyperhomocysteinemia. CASE PRESENTATION A 65-year-old Caucasian man complained of pain and constipation, attributed to previously diagnosed adenocarcinoma (stage IIB) of the hepatic flexure. An anamnestic investigation showed that he had undergone two surgical interventions. During both, he suffered thrombotic postoperative complications, a deep vein thrombosis of the upper extremity after the first operation and retinal vein occlusion after the second. He was diagnosed with hyperhomocysteinemia associated with a homozygous C677T mutation of the gene encoding the enzyme methylenetetrahydrofolate reductase. Our patient was initially treated with folic acid and high-dose B vitamins. On day 7 he underwent a right hemicolectomy. Anesthesia was performed with sevoflurane in 40% O2 and without the use of nitrous oxide. Postoperatively, our patient remained on folic acid and B vitamins and was without immediate or subsequent complications. CONCLUSIONS Neoplastic disease and related surgery followed by the administration of chemotherapeutic drugs alter the hemostatic balance in cancer patients. Those suspected of also having a thrombophilic disease require a thorough laboratory diagnostic workup, including a molecular analysis aimed at identifying the genetic mutation responsible for the hyperhomocysteinemia, as indicated. The case described in this report highlights the importance of a multidisciplinary approach that includes expertise in peri-operative anesthesia, surgery, oncology, and hematology.
3.
Survival and psychomotor development with early betaine treatment in patients with severe methylenetetrahydrofolate reductase deficiency.
Diekman, EF, de Koning, TJ, Verhoeven-Duif, NM, Rovers, MM, van Hasselt, PM
JAMA neurology. 2014;(2):188-94
Abstract
IMPORTANCE The impact of betaine treatment on outcome in patients with severe methylenetetrahydrofolate reductase (MTHFR) deficiency is presently unclear. OBJECTIVE To investigate the effect of betaine treatment on development and survival in patients with severe MTHFR deficiency. DATA SOURCES MEDLINE, EMBASE, and Cochrane databases between January 1960 and December 2012. STUDY SELECTION Studies that described patients with severe MTHFR deficiency who received betaine treatment. DATA EXTRACTION AND SYNTHESIS We identified 15 case reports and case series, totaling 36 patients. Data included the following: (1) families with 2 or more patients with severe MTHFR deficiency, of whom at least 1 received betaine, or (2) single patients with severe MTHFR deficiency treated with betaine. To define severe MTHFR deficiency, methionine, homocysteine, MTHFR enzyme activity in fibroblasts, or mutations (in the MTHFR gene) had to be described as well as the effect of treatment (survival and/or psychomotor development). We compared the outcome in treated vs untreated patients and early- vs late-treated patients. Sensitivity analysis was performed to address definition of early treatment. To further assess the impact of treatment on mortality, we performed a subanalysis in families with at least 1 untreated deceased patient. MAIN OUTCOMES AND MEASURES Survival and psychomotor development. RESULTS Eleven of 36 patients (31%) died. All deaths occurred in patients who did not receive treatment or in patients in whom treatment was delayed. In contrast, all 5 early-treated patients survived. Subgroup analysis of patients with deceased siblings-their genotypically identical controls-revealed that betaine treatment prevented mortality (P = .002). In addition, psychomotor development in surviving patients treated with betaine was normal in all 5 early-treated patients but in none of the 19 surviving patients with delayed treatment (P < .001). CONCLUSIONS AND RELEVANCE Early betaine treatment prevents mortality and allows normal psychomotor development in patients with severe MTHFR deficiency, highlighting the importance of timely recognition through newborn screening.