FLNA and Terminal osseous dysplasia - pigmentary defects: In contrast, gain‐of‐function variants could cause a series of skeletal dysplasias that are characterized by cleft palate, hyperostosis of the skull, anomalies of the tubular bones, which are mainly classified into otopalatodigital syndrome type I (OPD1, OMIM# 311300), otopalatodigital syndrome type II (OPD2, OMIM# 304120), fronto‐metaphyseal dysplasia 1 (FMD1, OMIM# 305620), Melnick‐Needles syndrome (MNS, OMIM# 309350), and terminal osseous dysplasia (TOD, OMIM# 300244) (Hehr et al., 2006).