Although in humans there are 22 pairs of autosomal chromosomes, only three different chromosomal trisomies are commonly seen in newborns. of the remaining 19 autosomes, many trisomies have not been seen in newborns. why not?

trisomy for the other autosomal chromosomes is often lethal, and the affected embryos are miscarried. trisomy for these other autosomal chromosomes occurs so rarely that it has never been documented. trisomy for these autosomal chromosomes has no effect and therefore would never be noticed. these autosomal chromosomes do not contain the same type of dna or protein that makes up chromosomes susceptible to trisomy.