Y chromosome 
XX male 
XY female 
The tiny region of the human Y chromosome implicated in both sex determination and Turner 
syndrome is shown in expanded view below the schematic diagram of the entire Y chromosome 
( the black oval represents the centromere of the Y chromosome). The region contains the genes 
SRY, RPS4Y, and ZFY. The black lines at the bottom of the diagram depict the portion of the Y 
present in two pivotal patients, one an XX male and the other an XY female (lacking features of 
Turner syndrome). 
Research of David C. Page. 
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