Trisomy 13 is a chromosome condition that causes severe learning disability and distinctive physical features. It is caused by having an extra copy of chromosome 13 and can be inherited or occur randomly. Trisomy 13 was first described as the cause of a distinct clinical syndrome in 1960 by Dr. Patau et al. The clinical syndrome was initially characterized as "cerebral defects, apparent anophthalmia, cleft palate, hare lip, simian creases, trigger thumbs, polydactyly, and capillary hemangiomata." Patau syndrome (also called Trisomy 13) is a genetic disorder caused by the presence of 3 copies of chromosome 13. Patau Syndrome (Trisomy 13) Trisomy 13, or Patau syndrome, is a genetic syndrome caused by the presence of 3 copies of chromosome 13. As the 3rd most common trisomy, Patau syndrome has an incidence of 1 in 10,000 live births and is more common in women. Most cases of Patau syndrome are diagnosed prenatally by maternal screening and ultrasound.
