KAT6B and genitopatellar syndrome: Heterozygous mutations in the KAT6A gene result in Arboleda-Tham syndrome (ARTHS)33,34, while mutations in the KAT6B gene result in the Say-Barber-Biesecker-Young Simpson variant of Ohdo syndrome (SBBYSS)35 or Genitopatellar syndrome (GPS)36.