<unk>  is classified as any congenital developmental disorder of the reproductive system in the male or female. It is the atypical development of the gonads in an embryo, with reproductive tissue replaced with functionless, fibrous tissue, termed streak gonads. Streak gonads are a form of aplasia, resulting in hormonal failure that manifests as sexual infantism and infertility, with no initiation of puberty and secondary sex characteristics.<unk>  development is a genetically controlled process by the chromosomal sex (XX or XY) which directs the formation of the gonad (ovary or testis). Differentiation of the gonads requires a tightly regulated cascade of genetic, molecular and morphogenic events. At the formation of the developed gonad, steroid production influences local and distant receptors for continued morphological and biochemical changes. This results in the appropriate phenotype corresponding to the karyotype (46,XX for females and 46,XY for males).<unk>  arises from the failure of signalling in this tightly regulated process during early foetal development. Manifestations of<unk>  are dependent on the aetiology and severity of the underlying defect.
Gonadal dysgenesis
Thyroid dysgenesis
XY gonadal dysgenesis
Cryptorchidism
Primordial dwarfism
Müllerian agenesis
Renal agenesis
Supernumerary kidney