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- What is XX male syndrome?
46,XX male syndrome is a DSD characterized by unambiguous male pheno-
type with 46,XX karyotype, varying degree of virilization, short stature, small
testes, primary infertility, and gynecomastia. The consistent biochemical
abnormality is elevated FSH, whereas serum LH levels are variable depending
on the degree of Leydig cell failure. SRY gene which is important for male sex
determination is translocated on pseudoautosomal region of X chromosome
and consequent male phenotype with 46,XX karyotype. The germ cell failure
occurs as a result of absence of azoospermia factor (AZF) which is present on
Y chromosome or due to presence of two X chromosomes.dFig. 9.19 (continued)
9 Disorders of Sex Development