1.
[Two cases with generalized intracranial calcification due to hereditary folate malabsorption and literature review].
Zhang, Y, Wang, Q, Li, DX, Liu, YP, Song, JQ, Li, MQ, Qin, YP, Yang, YL
Zhonghua er ke za zhi = Chinese journal of pediatrics. 2016;(12):931-935
Abstract
Objective: This study aimed to investigate the clinical, biochemical and genetic features of two Chinese children with hereditary folate malabsorption. Method: Clinical features, laboratory examinations, treatment and SLC46A1 gene of two cases were studied. Reports on hereditary folate malabsorption utill September of 2016 were searched and the clinical and genetic characteristics of reported cases were summarized. Result: The two patients presented with megaloblastic anemia from their infant period and seizures, psychomotor retardation and regression. In case1, mean corpuscular volume (MCV) was 100 fl. Serum folate was 9.96 nmol/L. Folate and 5-methylenetetrahydrofolate in cerebrospinal fluid were 0 and 0.01 separately. In case 2, MCV was 93.9 fl. Serum folate was 4.49 nmol/L. The concentration of folate and 5-methylenetetrahydrofolate in cerebrospinal fluid were both zero. On their brain CT, progressive bilateral symmetrical calcification was observed. On their SLC46A1 gene, four mutations were identified. Case 1 had one novel mutation, c. 1238T>C (L413P) and c. 194-195insG (p.Cys66LeufsX99). From Case 2, two reported mutations, c. 1A>T (M1L) and c. 194-195insG (p.Cys66LeufsX99) were identified. The administration of folinic acid (60 to 120 mg per day) was initiated after diagnosis. Clinical improvement and normalized hematologic markers were observed after treatment. Totally 37 cases were reported in reviewed English literature, including 30 cases with mutations on SLC46A1 gene (only one Chinese patient). All the cases had the onset in infancy. The ratio of boys to girls was 1 to 1.5. Main manifestations were characterized by megaloblastic anemia (77%), failure to thrive (50%), diarrhea (27%), psychomotor retardation (63.6%), epilepsy (27%), and infection of respiratory system (45.5%). The concentration of folate in both serum and cerebrospinal fluid was decreased (72.7% and 63.6% respectively). Hypoimmunoglobulinemia accounted for 27.3%. Most of mutations in HFM were distributed between p. 65 and p. 68 (c.194-c.204), mainly due to insertion- or deletion-related frame shifts or generation of stop codons. Oral and parenteral folinic acid treatment was effective. Conclusion: Hereditary folate malabsorption often presented with megaloblastic anemia, abnormalities of digestive and nervous system, and hypoimmunoglobulinemia with recurrent infections. Low level of serum and CSF folate and screening SLC46A1 gene are keys to the etiologic study of the patients. Early supplement with folinic acid is beneficial to the prognosis.
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Characterization and review of MTHFD1 deficiency: four new patients, cellular delineation and response to folic and folinic acid treatment.
Burda, P, Kuster, A, Hjalmarson, O, Suormala, T, Bürer, C, Lutz, S, Roussey, G, Christa, L, Asin-Cayuela, J, Kollberg, G, et al
Journal of inherited metabolic disease. 2015;(5):863-72
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Abstract
In the folate cycle MTHFD1, encoded by MTHFD1, is a trifunctional enzyme containing 5,10-methylenetetrahydrofolate dehydrogenase, 5,10-methenyltetrahydrofolate cyclohydrolase and 10-formyltetrahydrofolate synthetase activity. To date, only one patient with MTHFD1 deficiency, presenting with hyperhomocysteinemia, megaloblastic anaemia, hemolytic uremic syndrome (HUS) and severe combined immunodeficiency, has been identified (Watkins et al J Med Genet 48:590-2, 2011). We now describe four additional patients from two different families. The second patient presented with hyperhomocysteinemia, megaloblastic anaemia, HUS, microangiopathy and retinopathy; all except the retinopathy resolved after treatment with hydroxocobalamin, betaine and folinic acid. The third patient developed megaloblastic anaemia, infection, autoimmune disease and moderate liver fibrosis but not hyperhomocysteinemia, and was successfully treated with a regime that included and was eventually reduced to folic acid. The other two, elder siblings of the third patient, died at 9 weeks of age with megaloblastic anaemia, infection and severe acidosis and had MTFHD1 deficiency diagnosed retrospectively. We identified a missense mutation (c.806C > T, p.Thr296Ile) and a splice site mutation (c.1674G > A) leading to exon skipping in the second patient, while the other three harboured a missense mutation (c.146C > T, p.Ser49Phe) and a premature stop mutation (c.673G > T, p.Glu225*), all of which were novel. Patient fibroblast studies revealed severely reduced methionine formation from [(14)C]-formate, which did not increase in cobalamin supplemented culture medium but was responsive to folic and folinic acid. These additional cases increase the clinical spectrum of this intriguing defect, provide in vitro evidence of disturbed methionine synthesis and substantiate the effectiveness of folic or folinic acid treatment.
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Clinical trial of low-dose leucovorin plus 5-fluorouracil for patients with metastatic colorectal cancer.
Yamaguchi, Y, Sawamura, A, Minami, K
Hepato-gastroenterology. 2007;(77):1394-7
Abstract
BACKGROUND/AIMS: To establish an effective and practical treatment of Japanese patients with metastatic colorectal cancer in an outpatient setting, we conducted a clinical trial using a modified Mayo regimen. METHODOLOGY A bolus injection of low-dose (20 mg/m2) d,l-leucovorin (LV) was administered, followed one hour later by an intravenous injection of 333 mg/m2 5-fluorouracil (5-FU) for another hour. The two drugs were given on days 1, 2, and 3, and the treatment was repeated every 2 weeks. RESULTS In the 17 patients enrolled in the study, the tumor response rate was 25%, and time-to-treatment failure and median survival time were 7 and 24 months, respectively. The treatment was well tolerated, with no adverse effects greater than grade 3, and could be completed in all patients in the outpatient setting. One patient with lung, liver, and parailiac lymph node metastasis showed a complete response and survived for more than 6 years with tumor-free status. CONCLUSIONS These results suggest that although the sample size studied was too small to allow us to draw definitive conclusions, this regimen may be an effective and practical alternative to the Mayo regimen in an outpatient setting for Japanese patients with metastatic colorectal cancer.