FBN1 and Alzheimer disease: Some patients with pathogenic FBN1 variants had features that are different from or even opposite to the manifestations of MFS, such as the skin thickening in stiff skin syndrome (SSS, OMIM: 184900), progeroid appearance in marfanoid–progeroid–lipodystrophy syndrome (MFLS, OMIM: 616914), and short extremities in acromelic dysplasia, which include geleophysic dysplasia (GD, OMIM: 231050), acromicric dysplasia (AD, OMIM: 102370), and type II Weill-Marchesani syndrome (WMS2, OMIM: 608328) (Loeys et al., 2010b; Sakai and Keene, 2019; Muthu and Reinhardt, 2020; Yang et al., 2021).