Gonadal Dysgenesis (includes Turner Syndrome, others)
- both uterus and vagina are present,but infantile.
- secondary female sex characteristics (breasts, sexual hair) absent.
- hence serum estradiol levels are low
- other hormone assays are in the normal female range.
- less common is 46,XX with one of the two X chromosomes showing deletion (loss) of part or all of the respective short or long arm.
- absence of a Barr body on a buccal smear sample indicates absence of a second X chromosome.
- long term estrogen and progestin replacement
- growth hormone therapy (see Saenger, 1996)
Special Forms of Gonadal Dysgenesis - Primary Amenorrhea
- if the mosaicism is 45,X / 46,XX and the patient has primary amenorrhea, the gonadal status is the same as one with a 46,X karyotype.
- if the mosaicism is complex, e.g. 45,X / 46,XY the patient has what is termed mixed gonadal dysgenesis and the phenotype may range from that usually associated with the Turner syndrome to that of a normal male, although the vast majority or the latter have some external genital ambiguity or testicular maldescent.
- such cases are genetic, either autosomal recessive or X-linked, and have normal stature and usually no somatic abnormalities.
- in these individuals the streak gonads should be considered as dysgenetic, non-functional testes rather than ovaries and should be removed because of a greatly increased risk of neoplasia
- this form of gonadal dysgenesis is genetic but heterogeneous ; i.e. either autosomal or X-linked genes may be responsible. End of Page