SMAD6 and microcephaly: For example, one infant had four possible genetic disorders and one probable genetic disorder (SMAD6–Aortic valve disease 2, MIM:614823, probable genetic etiology; BMP2–Short stature, facial dysmorphism and skeletal anomalies with or without cardiac anomalies 1, MIM:617877; GLI2–Holoprosencephaly 9, MIM:610829; NKX2–1–Choreoathetosis, hypothyroidism and neonatal respiratory distress, MIM:610978; and TRIO–Intellectual developmental disorder with microcephaly 44, MIM:617061).