Partial androgen insensitivity syndrome (PAIS)
is a disorder of sex development that affects the growing reproductive and genital organs of a fetus. Androgen insensitivity refers to the inability of the body of an individual with a 46, XY karyotype (usually leading to normal male development) to properly respond to male sex hormones (androgens). In PAIS, the body partially responds to these hormones. Signs and symptoms of PAIS can vary greatly, causing a range of differences in genital appearance. Some individuals have severe hypospadias, an unusually small penis, and bifid scrotum. More severely affected individuals may have female external genitalia with an abnormally large clitoris, partial fusion of the labia and gynecomastia (excessive development of male breasts). In the least severe cases, the only symptom may be infertility. PAIS It is inherited in an X-linked recessive manner and is caused by mutations in the AR gene. Treatment depends on severity and whether the individual is being raised as male or female; management may include surgery, hormone replacement and psychological support. - Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.