Gonadal dysgenesis is classified as any congenital developmental disorder of the reproductive system in humans. It is atypical development of gonads in an embryo. One type of gonadal dysgenesis is the development of functionless, fibrous tissue, termed streak gonads, instead of reproductive tissue. 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. Gonadal development is a process, which is primarily controlled genetically by the chromosomal sex (XX or XY), which directs the formation of the gonad (ovary or testicle). 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 phenotype corresponding to the karyotype (46,XX for females and 46,XY for males). Gonadal dysgenesis arises from a difference in signalling in this tightly regulated process during early foetal development. Manifestations of gonadal dysgenesis are dependent on the aetiology and severity of the underlying causes.

Reference
Wiki: Ovarian dysgenesis