Involvement of C677T MTHFR variant but not A1298C in methotrexate-induced toxicity in acute lymphoblastic leukemia

Background Methotrexate (MTX) is a key drug in acute lymphoblastic leukemia (ALL) treatment; it inhibits DNA replication by blocking the conversion of 5, 10 Methylenetetrahydrofolate to 5-methylene tetrahydrofolate by methylenetetrahydrofolate reductase (MTHFR). Variants of the Methylenetetrahydrofolate reductase (MTHFR) and MTX related toxicities were largely investigated in several populations, nevertheless, the results are conflicting. Objective This study aimed to assess the prevalence of MTHFR SNVs: C677>T and A1298>C in Tunisian patients with ALL and the relation to the frequency of drug-induced complications. Methods 28 ALL patients were included in the study. They were treated according to EORTOC, in which a high dose of MTX (HDMTX) was prescribed. A toxicity score (ST) is calculated for each patient, summing the grades of toxicities. Genotyping of MTHFR variants was done with a PCR-based restriction fragment length polymorphism assay. Results The toxicity’s score (TS) was higher with C677T variant compared to wild genotype (C677C) (TS = 4; IC95% [−2.65–13.32] versus TS = 2.5; IC95% [1.65–4.55], respectively; p = 0.2); but lower with the A1298C mutation compared to those with the wild genotype (A1298A) (TS = 2.5; IC95% [0.48–4.77], versus TS =3; IC95% [1.9–5.69], p = 0.4). HDMTX-related toxicity is associated with the 677CT genotype in ALL patients (RR = 1.41, p = 0.2); not for the A1298C [OR = 0.46, [0.08–2.61], p = 0.18]. Conclusion Our preliminary findings highlight the impact of the C677T variant of MTHFR, but not the A1289C; in HD-MTX chemotherapy-related adverse effects in younger Tunisian ALL.

Acute myocardial infarction in a premature infant on the first day of life

Neonatal myocardial infarction (MI) is a very rare but potentially life-threatening condition with an approximated mortality rate of 80%. Congenital heart disease, anomalous coronary artery anatomy, thromboembolism, coagulopathy, birth asphyxia or myocarditis have been suggested as possible causes of MI. Here we report the case of a premature infant who died at about 40 h of life from a massive MI. Autopsy revealed an occlusive thrombus in the right coronary artery. An isolated prothrombotic status, characterized by a double copy variant of the MTHFR A1298C mutation, was identified at the postmortem genetic studies as a possible explanation for the coronary artery thrombosis. No other risk factors were detected.

Severe Arterial Thrombophilia Associated With a Homozygous MTHFR Gene Mutation (A1298C) in a Young Man With Klinefelter Syndrome

Klinefelter syndrome (KS) is the most common sex chromosome disorder in men. It may be associated with an increased risk for venous thrombosis and thromboembolism, which is partially explained by hypofibrinolysis due to androgen deficiency. Additional genetic or acquired thrombophilic states have been shown in KS patients complicated with venous thrombosis as isolated case reports. Arterial thrombotic events had not been previously reported in KS. In this study, a young man with KS who developed acute arterial thrombosis during testosterone replacement therapy is presented. He was homozygous for the A1298C mutation of the methylenetetrahydrofolate reductase (MTHFR) gene.

Familial Perinatal Liver Disease and Fetal Thrombotic Vasculopathy

The association between placental fetal thrombotic vasculopathy (FTV) and perinatal liver disease was not recognized until 2002, when Dahms and colleagues reported a series of 3 patients in whom severe liver disease developed in the first 2 days of life. All had abnormal liver histology and showed a variety of abnormalities, including Budd-Chiari syndrome, changes mimicking extrahepatic obstruction, lobular fibrosis, cholestasis, and hepatocyte giant cell transformation. We report recurrent significant perinatal liver disease in a family, associated with proven FTV in at least 1 pregnancy. A 30-year-old gravida 4 female with a history of heterozygous methylenetetrahydrofolate A1298C mutation had a normal 1st pregnancy and then experienced an intrauterine fetal demise at 38 weeks of gestation. Placental examination revealed extensive occlusive and mural thrombi of chorionic vessels associated with a large focus of avascular villi. Histologic examination of the liver showed extensive giant cell transformation and hepatocyte dropout. No excess hemosiderin pigment was present in the liver, pancreas, or heart. A 3rd pregnancy produced a live-born term infant with transient neonatal cholestasis. The 4th pregnancy also produced a term neonate who presented with acute hepatic failure of unknown cause, ultimately requiring liver transplantation. Fetal thrombotic vasculopathy is an underrecognized association with perinatal liver disease that may be associated with abnormal liver perfusion and that may recur in families, especially when a genetic thrombophilia is present.