Yes. Although the normal number of chromosomes is 46, some people are born with less (e.g., people with Turner's syndrome have 45) and some people are born with more (e.g., people with Down's syndrome have 47). But don't forget that the case for the unborn's humanness does not rest necessarily on the number of chromosomes an individual may have, but on the fact that the entity in question has a human genetic structure. Consequently, a human genetic structure can still subsist in an abnormal number of chromosomes (genes are contained in the chromosomes within the nuclei of a person's cells).
That is to say, the Down's or Turner's syndrome child with human genes and an abnormal number of chromosomes is no more nonhuman than a child with an abnormal number of more obvious parts.
For example, a person born with six fingers is human, as is a person born with one arm or one leg.
Author: Francis J. Beckwith, adapted from a series in Christian Research Journal, Spring 1991. Provided with permission by Summit Ministries and the author.
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