Plexins are receptors for Semaphorin signalling proteins. Semaphorin-plexin signalling controls cellular interactions that are critical during development and in adult life stages. We identified biallelic variants in Plexin B2 (PLXNB2) through exome or genome sequencing in eight people from six families, each of whom have a syndromic condition including amelogenesis imperfecta and hearing loss. Intellectual disability, ocular disease, ear developmental abnormalities and lymphoedema were also reported in multiple individuals but were not universal. The variable syndromic features and the rarity of these disease causing variants may be why pathogenic variants in PLXNB2 have not been previously reported. (By Dr Claire E L Smith, https://jmg.bmj.com/content/early/2024/03/08/jmg-2023-109728 )