Chromosomal (genetic) amenorrhea
1- Turner syndrome (ovarian dysgenesis):
2- Androgen insensitive syndrome; (AIS):
♦ Synonyms; Testicular feminization syndrome, gonadal dysgenesis,
target organ amenorrhea.
– Chromosomal composition of this condition is 46 XY (male).
– Inherited disorder (X linked recessive gene) affecting androgen receptors in breast, hair follicles and vulva.
– The previous tissues become insensitive to androgen secreted by the testes and so they develop in the female direction so the newborn is identified as a female. Clinical phenotypes range from a normal male habitus with mild spermatogenic defect or reduced secondary terminal hair, to a full female habitus.
– At puberty, breast development and feminine contour develops also, in response to estrogen comes from peripheral conversion of testicular androgen.
– Appearance; – Very attractive female,
– Well developed cubic breasts é small
nipples & pale areola.
– Skin; Smooth, hairless and lustrous.
– Hair; – Scalp hair is silky,
– Pubic and axillary hairs are absent or scanty.
– Genital tract; * fallopian tubes and uterus are absent or rudimentary, so there is,
– Primary amenorrhea,
– The vagina is short and blind,
– The gonads (testes) are intraabdominally or in the groins or upper labia.
– Medical; estrogen (avoid menopausal symptoms, osteoporosis & CHD).
– Removal of testes; (carcinogenic 2-25%) after puberty (16-18 years).
– Artificial neovagina (Mc Indoe or William operation).
♦ Karyotyping 47XXX or 48XXXX.
* Clinical picture:
1- Mental deficiency up to retardation.
2- Genital; 1ry amenorrhea or oligomenorrhea.
3- Gonadal; infertility.
4- Infantile genital organs.
* Diagnosis; Buccal smear and karyotyping → two or more Barr bodies.
4- Klinefelter’s syndrome:
– Karyotyping 47XXY, additional X chromosomes may also exist.
– The cells are chromatin positive i.e. possess Barr bodies, but the individual is physically a male (effect of Y chromosome).
– At puberty however, the testes fail to develop more and so;
– Facial hair is scanty, and
– Pubic hair posses a feminine manner.
– The individual is infertile and may posses some breast development.
Chromosomal (genetic) amenorrhea. Which Genetic disease caused by nondisjunction of Chromosomes?
Turner syndrome or Ullrich–Turner syndrome (also known as “Gonadal dysgenesis” 550), 45,X, encompasses several conditions in human females, of which monosomy X (absence of an entire sex chromosome, the Barr body) is most common. It is a chromosomal abnormality in which all or part of one of the sex chromosomes is absent or has other abnormalities (unaffected humans have 46 chromosomes, of which two are sex chromosomes). In some cases, the chromosome is missing in some cells but not others, a condition referred to as mosaicism or “Turner mosaicism”.