One study [27] proposed the risk for Alzheimer’s disease is most likely associated with the B allele of CR1 (CR1-B, equivalent to CR1long in this study), with one copy of CR1-B carrying a 1.8x higher risk of disease over the CR1-A/A allele (equivalent to CR1short in this study) and a faster rate of cognitive decline. This evidence concerns the gene CR1 and early-onset autosomal dominant Alzheimer disease.