A baby girl presents with bilateral inguinal masses, thought to be hernias but are found to be tested in the inguinal canals. Which karyotype would you expect to find in the child -
46,XX
46, XY
47, XXY
47, XYY
It is a case of Testicular feminisation syndrome.
The characteristic features of these disorders are that they are genotypically male (X19 while phenotypically they are female.
These cases usually present as a 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 herniorrhapy in phenotypically female.
It is called testicular feminisation syndrome but the name is both stigmatising and inaccurate (the testes do not produce feminising factors).
The preferred name, complete androgen insensitivity syndrome (CAIS) reflects the underlying aetiology.

The cause of androgen insensitivity syndrome is the abnormality of the androgen 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 secrete 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 virilise and instead undergo female development.
These patients have a vagina instead of a 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 the normal average length of 10-12 cm.
The cause of this lies in the embryological development of the vagina,

The upper portion of vagina → develops from Mullerian ducts
The lower portion of vagina → develops from urogenital sinus.


In CAIS Mullerian duct regresses, under the effect of the mullerian inhibiting hormone, leaving just the part derived from the urogenital sinus.

Clinical features of CAIS

Female external genitalia
46 XY karyotype
Intrabdominal or inguinal testes
Absent uterus
Primary amenorrhoea
Reduced or absent sexual hair (pubic and axillary)
Normal breast development
Vaginal hypoplasia