1 INTRODUCTION Split hand/foot malformation (SHFM) is a congenital limb disorder affecting 1 in 18,000 live births (Umair & Hayat, 2020). Individuals with SHFM present with missing, hypoplastic, and/or fused digits, though the phenotypes are highly variable due to incomplete penetrance. Many individuals also present with craniofacial defects, such as a cleft lip/palate, microdontia, micrognathia, and/or maxillary hypoplasia (reviewed in Sowinska-Seidler et al. (2014)).