rs5984894 is a SNP located within an intron of the protocadherin 11 PCDH11X gene, on the X chromosome.
A study of 2,391 patients with late-onset Alzheimer's disease reports that rs5984894 is particularly associated with increased risk for the disease in females, as compared to males. In this study, the patients were Americans of European descent, and 62% were female. Odds ratios were 1.75 (CI: 1.42–2.16) for female homozygotes (p = 2 x 10e-7) and 1.26 (CI: 1.05–1.51) for female heterozygotes (p = 0.01) compared to rs5984894(G;G) females.[PMID 19136949]
For male rs5984894(-;A) hemizygotes (p = 0.07, which may mean this is insignificant since it is above the traditional cut-off of 0.05) compared to male rs5984894(-;G) noncarriers, the odds ratio was 1.18 (CI: 0.99–1.41).[PMID 19136949]
A more recent and independent - but also smaller - study found no association between late-onset Alzheimer disease and rs5984894 in a dataset of 889 cases and 850 controls, indicating that "the PCDH11X association, if not a false positive, is not as strong or generalized as hypothesized earlier".[PMID 20523261]
[PMID 20555150] Failure to Replicate an Association of rs5984894 SNP in the PCDH11X Gene in a Collection of 1,222 Alzheimer's Disease Affected Patients
[PMID 20707987] Lack of association between PCDH11X genetic variation and late-onset Alzheimer's disease in a Han Chinese population
[PMID 19734902] Genome-wide association study identifies variants at CLU and PICALM associated with Alzheimer's disease.
[PMID 20574532] Intermediate phenotypes identify divergent pathways to Alzheimer's disease.
[PMID 26680604] Polygenic Analysis of Late-Onset Alzheimer's Disease from Mainland China.