CHROMOSOMAL ABNORMALITIES IN SEX DIFFERENTIATION ::
The abnormalities of the sexual development could be caused by genetic or hormonal abnormalities Excess of maternal androgen or adrenal hyperplasia of foetus may cause female pseudohermaphroditism whereas testicular feminization can cause male pseudohermaphroditism Among the chromosomal abnormalities major defect may be due to non -disjunction a phenomenon in which sex chromosomes fail to separate Thus one gamet may get both sex chromosomes while the other does not get any of the sex chromosome Due to this non disjunction four abnormal zygotes may be formed after fertilization
1.Gonadal dysgenesis ::
It is a defect in which a female gamet having no sex chromosome unites with male gamet containing X chromosome In such individuals with XO pattern the gonads are rudimentary or absent This syndrome is also known as ovarian oogenesis or Turners syndrome
2.44YO Patterns ::
If a female gamet having no sex chromosome unites with a male gamet having Y chromosome the resultant pattern is 44YO and this is mostly lethal
3.Superfemale ::
It is the second most common chromosomal defect resulting from the union of female gamet having XX chromosomes with male gamet containing X chromosome It is not associated with any characteristic abnormalities
4.Seminiferous tubule dysgenesis or klinefelter syndrome ::
This is the most common chromosomal defect having XXY pattern and results from the union of female gamet having XX chromosomes with male gamet containing Y chromosome Such individuals have the genitalia of a normal male Testosterone secretion at puberty is often great enough for the development of male characteristics However the seminiferous tubules are abnormal and there is a higher risk than normal incidence of mental retardation
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