In addition, although the pathogenic variants and application of next-generation sequencing have improved the genetic diagnosis of MFDM, its broad and heterogeneous phenotypic spectrum and numerous variants of uncertain significance complicates the molecular etiologic diagnosis and supports the importance of documenting the pathogenic effects of EFTUD2 variants. Here, EFTUD2 is linked to mandibulofacial dysostosis-microcephaly syndrome.