Is there an association of regulatory region polymorphism in the alpha-1-antichymotrypsin gene with sporadic Alzheimer' s disease in the northern Han-Chinese population?

Both in vitro and in vivo alpha-1-antichymotrypsin (ACT) directly inhibits amyloid beta peptide (A beta ) degradation and promotes A beta deposition. However, whether the genetic variants in the regulatory region (including the promoter and the two enhancers) of the ACT gene affect susceptibility to Alzheimer's disease (AD) remains controversial. Here, we screened ACT promoter and enhancers in 244 patients with sporadic Alzheimer's disease (SAD) and 205 control patients, both of north Han-Chinese origin. Four single nucleotide polymorphisms (SNP) were found: (i) 11510T/C (rs10145747, named as ACT1); 11496G/A (rs4375593, ACT2); (iii) 11491T/C (rs4508366, ACT3); and (iv) 51G/T (rs1884082, ACT4). Neither individual SNP nor haplotypes were associated with AD onset. We concluded that the effect of the variations in the ACT regulatory region must be very limited, if occurring at all.