Among these, MYMK variants were identified in two individuals: an affected child from the USA who had been misdiagnosed with Moebius syndrome inherited M1 from her father and c.2T>A (p.0?, M4) from her mother (Family 4, individual 7); and an affected child from a consanguineous Brazilian pedigree diagnosed with CFZS was homozygous for a c.461T>C (p.Ile154Thr, M5) variant (Family 5, individual 8; the affected sibling was not enrolled in the study; Fig. 1a, Table 1, Supplementary Fig. 1a). Here, MYMK is linked to Moebius syndrome.