YY Chromosome Combination
Name: John J.
Is it possible for a person to be born with YY sex
Missing the X chromosome completely is lethal to my knowledge. I also know
of no cases of live birth to a human with no x chromosomes. XYY is possible
and does occur. XYY can be normal although some evidence indicates they are
sometimes below normal inteelect and sometimes violent.
Peter Faletra Ph.D.
Office of Science
Department of Energy
No, the Y chromosome does not have a full complement of genes that the X
chromosome contains. An individual must have at least one X chromosome to
It is possible for a person to INHERIT two Y chromosomes, but the embryo
would fail to thrive and be miscarried. Remember that the X chromosome has
many characteristics on it that have nothing to do with gender and that are
necessary for life.
Updated -- 04/03/01
Just recently it was discovered that the X chromosome has the primary role in
sperm production in males. This alters our view of the X-Y chromosome operation.
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Update: June 2012