<prompt> Patau syndrome due toTrisomy 21Trisomy 1818 PTrisomy l3  <response>: PATAU SYNDROME:- Trisomy 13 47 XX Characteristic features:- 1. Microcephaly and mental retardation. 2. Microphthalmia 3. Cleft lip and palate. 4. Cardiac and renal defects 5. Umbilical hernia 6. Rocker bottom feet Reference:Robbins basic pathology 9E pg no.248 