How many down syndrome people were killed in the holocaust?

Between 1939 and 1941, 80,000 to 100,000 mentally ill adults in institutions were killed; 5,000 children in institutions; and 1,000 Jews in institutions. Outside the mental health institutions, the figures are estimated as 20,000 (according to Dr. Georg Renno, the deputy director of Schloss Hartheim, one of the euthanasia centers) or 400,000 (according to Frank Zeireis, the commandant of Mauthausen concentration camp). Another 300,000 were forcibly sterilized. Overall it has been estimated that over 200,000 individuals with mental disorders of all kinds were put to death