PLXND1 and cartilage-hair hypoplasia: Studies in Chinese cohorts identified novel loss-of-function SEMA3A variants (NM_006080: c.1369A>G, p.T457A; c.1850G>A, R197Q; c.1850G>A, R617Q; c.1372G>A, V458I) in male normosmic CHH patients, some of whom also carried variants in other genes including PLXNA4, PLXND1 and FGFR1 [73, 74].