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Deletions in chromosome Y |
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In cases where there is a deletion of part of the short arm of chromosome Y,
a female phenotype is found because of the deletion of a gene called SRY that is responsible for
testicular development.
This condition is rare.
Deletions in the long arm of chromosome Y that do not cause a loss of the normal male phenotype but
that may be associated with the absence of sperm formation are more common.
In most of these cases the deletion is in a region that does not encode genes and thus has no
clinical significance.
If a short Y chromosome is identified, the father should be examined.
When the father's Y chromosome is identical to that found in the fetus, the deletion has no
significance, but when the father does not have an identical Y chromosome structure, and paternity
is not in doubt, the deletion in the fetus may have consequences for the offspring's final height
and sterility (because of a lack of sperm cells), although these conditions can be treated.
Some men who are sterile have deletions in certain regions of the long arm of the Y chromosome.
These can be detected using molecular methods.
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