Pure Gonadal Dystrophy (
Pure /complete gonadal dysgenesis, XY gonadal
dysgenesis or Swyer syndrome is a type of hypogonadism in a person whose
karyotype is 46, XY. The person is externally female with streak gonads, and
left untreated, will not experience puberty. The term “pure gonadal dysgenesis”
has been used to describe conditions with normal sets of sex chromosomes as
opposed to those whose gonadal dysgenesis results from missing all or part of
the second sex chromosome. Patients with PGD have a normal karyotype but may
have mutations in SF1,
SRY, DH1 and
NR5A1 genes. Presently, the database contains information for the first
three genes. While SRY related PGD is Y-linked, DHH related on is X-linked and
that with SF1 is autosomal recessive.
Androgen insensitivity syndrome (
insensitivity syndrome is X-linked recessive disorder in which affected males
have typical female phenotype in spite of normal male 46,XY karyotype.
Mutations in the androgen receptor gene AR
mapped to chromosome Xq, is responsible for this disorder.