With rare exceptions
includes the most common form, trisomy 21, translocations(a small amount of extra 21) & mosaics with some normal and some 21 trisomy(two kinds of cells).
The eventual growth expected would depend some on the type. For the common t21 the tallest 10% of males reach 67-71" compaired with 73-74" for normal. Similar differences are seen in girls. See www.Ncbi.Nih.Gov/pmc/articles.