USP6NL and Alzheimer disease: Missense variants in nine genes co‐segregated with APOE ε4, including ABCA1, AKAP9, ANK3, CTSB, EED, PRDM7, SNX1, USP6NL, and WDR81 in the AD‐FBS families, while in the EFIGA families APOE ε4 segregated with missense variants in ADAMTS20, AKAP9, ANK3, CR1, SORL1, and TSPOAP1.