KMT2D and hydrops fetalis: KMT2D mutations cause Kabuki syndrome, which is characterised postnatally by developmental delay, epilepsy, cardiac, genitourinary and musculoskeletal anomalies, and distinctive facial features.41, 42, 43, 44 Although the presentation of KMT2D mutations with fetal hydrops has been reported previously,44, 45 the distinctive facial dysmorphology is less apparent in infancy than older children, which makes diagnosis difficult during the early postnatal period.