Revision on Abnormalities of sex determination and differentiation,Disorders of puberty
1.TURNER'S SYNDROME
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-gonadal dysgenesis/ovarian dysgenesis
-also known as Bonnevie-Ullrich syndrome;monosomyx
-45,XO-sterile female
-meiotic.mitotic non disjunction
-sex chromatin absent
-external gernitalia of female may be present
-most XO fetuses die before birth
-low plasma estradiol
-High plasma LH and FSH concentration
Possible symptoms in young infants:
-wide and webbed neck
-imature internal sensual organ
-swollen hands and feet
In older females:
-short stature
-absent or incomplete development of puberty,including sparse pubic hair and small breast
-nipples wide apart at most extreme point.
-broad flat chest,shaped like a shield
-drooping eyelids
-dry eyes
-infertility
-primary amenorrhea
-vaginal dryness,lead to painful intercourse
2 Klinefelter's syndrome
-A syndrome affecting males in which the cells have an extra X chromosome (in addition to the normal XY), characterized by a tall thin physique, small infertile testes, and enlarged breasts
-most common sex chromosome abnormality
-47,XXY
-non disjunction during 1st/2nd meiotic division in either parents.
-Mitotic nondisjunction
-Sex chromatin present.
Features:
-above average height.
-Have genitalia of a normal male.
-feminine features in an apparent male with small testis
-seminiferous tubules dysgenesis
-sterile male
-50% has bilateral gynaecomastia
-high incidence of mental retardation
3.TRUE HERMAPHRODISM
-presence in an individual of both ovarian and testicular tissues and of ambiguous morphologic criteria of sex
-individual has both testis and ovaries
mixture of XX and XY-monosaicism.
4.MALE PSEUDOHERMAPHRODITISM
PSEUDOHERMAPHRODITISM- A state in which an individual possesses the internal reproductive organs of one sex while exhibiting some of the external physical characteristics of the opposite sex. Also called false hermaphroditism.
-the individual is genetically male and has male gonads (testes) but has significant female secondary sex characters.
-Female external gernitalias in genetic male when embryonic testes defective.androgen resistance.
-puberty, LH secretion and circulating testosterone levels increased.thus they developed male libido and male body contours
-clitoris enlarges to the point that some of the individual can have intercourse with woman.
5.FEMALE PSEUDOHERMAPHRODITISM
-the individual is genetically female and has female gonads (ovaries) but has significant male secondary sex characters
-male genital development in genetic females after exposure to androgens during 8-13th weeks of gestation.
-congenital virilizing afrenal hyperplasia or androgen adminstered to mother.
6.DOWN'S SYNDROME
-Down syndrome (DS) is the most common cause of mental retardation and malformation in a newborn. It occurs because of the presence of an extra chromosome
Features:
-slanting,almond shaped eyes
-protruding tongue
-small,open mouth
-flat nose bridge
-flattened face
-small ears
7.True precocious puberty
-abnormally early development of sexual maturity.
-early development of secondary sexual characteristics with gametogenesis due to early but normal gonadotropin secretion from anterior pituitary.
- causes : -constitutional ,disorders involving posterior hypothalamus,gonadotropin independant precocity.
8.Precocious pseudopuberty
-early development of secondary sexual characteristics without gametogenesis due to abnormal exposure of immature males to androgen and females to estrogen.
-causes: adrenal-congenital virilizing adrenal hyperplasia , androgen/estrogen secreting tumours
gonadal- tumours of testis(leydig cells), tumours of ovary(granulosa cells).miscellaneous.
