Confirmation of the association between bleomycin hydrolase genotype and Alzheimer's disease

Bleomycin hydrolase (BH), a cysteine protease from the papain superfamily, is considered to be a candidate for the beta-secretase, which is presumably involved in the production of beta-amyloid peptide. The G/G genotype of BH was identified as a significant risk factor for the development of Alzheim er's disease (AD) in subjects not carrying the apolipoprotein E epsilon 4 a llele (apoE-epsilon 4). However, this finding was recently challenged. We s tudied this polymorphism in a homogenous sample of German AD patients and c ontrols. The over-representation of the G/G genotype in AD patients could b e confirmed, however it was more pronounced in apoE-epsilon 4 carriers. Add itional studies should be undertaken to increase the confidence that the BH polymorphism is associated with AD and to explore the relationship between BH and apoE.