Androgen insensitivity syndrome true is:
Ans. is 'a' i.e., Phenotype may be completely female Androgen Insensitivity syndrome (Testicular feminization syndrome)The characteristic features of these disorders are that they are genotypically male (XY) while phenotypically they are female.These cases usually present as female with abdominal testis.Prepubertal children with this disorder are often detected when inguinal masses prove to be a testis or when a testis is unexpectedly found during herniorrhaphy in phenotypically female.It is called testicular feminization syndrome but the name is both stigmatizing and inaccurate {the testes do not produce feminizing factors).The preferred name, complete androgen insensitivity syndrome (CAIS) reflects the underlying aetiology.The cause of androgen insensitivity syndrome is the abnormality of the and Rosen receptor.In the fetus with CAIS testes forms normally due to the presence of the (SRY gene) on chromosome Y.At the appropriate time, these testes secretes anti Mullerian hormone leading to the regression of mullerian ducts. Hence CAIS 'women' do not have a uterus.Testosterone is also produced at the appropriate time. However due to the complete inability of the androgen receptor to respond, the external genitalia do not Virilize and instead undergo female development.These patients have vagina instead of penis.Other areas where testosterone may have important fetal effects, such as the brain, will also develop along the female path. The result is a female (both physically and psychologically) with no uterus, testis present which is found at some point in their line of descent through the abdomen from the pelvis to the inguinal canal.During puberty, breast development will be normal,; however, the effects of androgens will not be seen, so pubic and axillary hair growth will be minimal.Majority of women with CAIS have shortened vagina, when compared with normal average length of 10-12 cm.The cause of this lies in the embryological development of the vagina, - Upper portion of vagina - develops from mullerian ducts- Lower portion of vagina - develops from urogenital sinus.In CAIS mullerian duct regresses, under the effect of mullerian inhibiting hormone, leaving just the part derived from the urogenital sinus. Clinical features of CAIS Female external genitalia46 xy karyotypeIntraabdominal or inguinal testesAbsent uterusPrimary amenorrhoeaReduced or absent sexual hair (pubic and axillary)Normal breast developmentVaginal hypoplasia
Phenotype may be completely female
Predominantly ovarian component in gonads
Always in female
Testes formed abnormally and receptors are normal
Genital Differentiation