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Name: John J.
Status: Other
Age: 30s
Location: N/A
Country: N/A
Date: N/A 

Is it possible for a person to be born with YY sex chromosomes?

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 survive.

Steve Sample

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.

Steve Sample

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