NAA10 and cardiac arrhythmia: The NAA10-related syndrome is characterized by wide phenotypic variability in both sexes, ranging from early lethality due to structural cardiac abnormalities and/or arrhythmias in males with the recurrent Ser37Pro variant, to a series of disorders reported in both males and females with other NAA10 variants, such as developmental delay, muscle hypotonia, skeletal abnormalities, recurrent infections, feeding difficulties, postnatal growth retardation, dysmorphism, ocular anomalies and cardiac abnormalities, including long QT syndrome.