The abnormal levels of the human carbonic anhydrase isoenzymesI and II (hCA I and II) and cholinesterase enzymes, namely, acetylcholinesterase(AChE) and butyrylcholinesterase (BChE), are linked with various disordersincluding Alzheimer’s disease. This evidence concerns the gene ACHE and early-onset autosomal dominant Alzheimer disease.