XX male syndrome occurs when the affected individual appears as a normal male, but has a female genotype (two X chromosomes). Two types of XX male syndrome can occur: those with detectable SRY gene and those without detectable SRY. SRY is the main genetic switch for determining that a developing embryo will become male.

XX male syndrome is a condition where the sex chromosomes of an individual do not agree with the physical sex of the affected person. Normally, there are 46 chromosomes, or 23 pairs of chromosomes, in each cell. The first 22 pairs are the same in men and women. The last pair, the sex chromosomes, is two X chromosomes in females (XX) and an X and a Y chromosome in males (XY).

With XX male syndrome, the person has female chromosomes but male physical features. The majority of persons with XX male syndrome have...