BHMT and Alzheimer disease: Betaine-homocysteine S-methyltransferase (BHMT) catalyzes the reversible methylation of homocysteine to methionine [27] and has been the subject of gained renewed interest after the discovery that the blood concentration of homocysteine is related to human health problems such as: thrombosis, vascular [28,29,30,31,32] and congenital diseases, such as spina bifida [33,34], as well as Alzheimer disease [35,36].