MTHFR and obesity due to melanocortin 4 receptor deficiency: MTHFR variant rs1801133 demonstrated significant 2‐df joint effects with each of sex, body mass index, fasting plasma glucose, HDL cholesterol, low‐density lipoprotein cholesterol, triglycerides, drinking, smoking, obesity, and history of hyperlipidemia on stroke (Meta‐P=2.7×10−11, 3.9×10−17, 1.1×10−15, 1.2×10−11, 7.5×10−12, 2.3×10−12, 2.5×10−12, 7.0×10−12, 8.4×10−17, and 7.2×10−9, respectively).