Pure gonadal dysgenesis will be diagnosed in the presence of :
Ans. is a i.e. Bilateral streak gonads Gonadal development is under the influence of sex chromosome.deg The testes determining gene is present on the Sex Determining Region of the Y chromosome (SRY)deg. Therefore when Y chromosome is present (even in presence of multiple X chromosomes) it leads to testes formation.deg When Y chromosome is absent and two complete X chromosomes are present, it leads to ovary formation.deg In females with 45X0 genotype : the gonads are replaced by fibrous tissue and are known as streak Gonads or Gonadal dysgensis and the syndrome is known as Turner Syndrome.deg The genes which protect against the physical malformations of Turner Syndrome are carried on sho arms of XX or XYchromosomesdeg and genes which protect against streak gonads are on the long arms of XX or XYdeg. dysgenesisdeg : In this disorder the individual has karyotype of 45X0 / 46XY and so there is a streak Gonad or no Gonad on one side (corresponding to 45X0) and a testis on the other side (corresponding to 46XY). Also know : Streak and dysgenetic Gonads have a high potential for neoplasia (especially dysgerminomadeg or Gonadoblastomadeg and Yolk sac tumordeg) if the owners karyotype contains a Y chromosome.
Bilateral streak gonads
Bilateral dysgenetic gonads
One side steak and other dysgenetic gonads
One side streak and other normal looking gonad