APOE and Pallister-Hall syndrome: Compared to atrophy score alone, the combined model of PHS and atrophy score was significantly more predictive of change in both MMSE (χ2 = 19.04, df = 1, p = 1.281e-05, [controlling for APOE ε4 alleles: χ2 = 6.97, df = 1, p = 0.008]) as well as CDR_SB (χ2 = 13.43, df = 1, p = 0.00025 [controlling for APOE ε4 alleles: χ2 = 4.57, df = 1, p = 0.033]).