Hereditary causes of infertility 1

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Hereditary causes of infertility 1

  1. 1. Hereditary Causes of Infertility By Dr. Atef Abdel-Hai Khalil Selmi Professor of Obstetrics, Gynecology, & A.I. Faculty of Veterinary Medicine Zagazig University ( 3 )
  2. 2. Hereditary Causes of Infertility 1-Freemartins Freemartins are sterile heifers (90%) born co-twin with males. Incidence of twinning varies greatly among breeds of cows ( 0.5-4.2% in Holstein-Friesian, 2.4-4.2% in Simmental, and 2.5-3.2% in Charolais). Most of twin births are dizygotic (90-99 %). This condition is a unique form of intersexuality characterized by abnormal developmental changes during sexual differentiation.
  3. 3. Developmental abnormalities leading to freemartins: 1-The sex of an individual can be determined at three levels, genetic, gonadal, and accessory genital organs. 2-Placental fusion and anastomosis takes place at about 20 days of gestation between chorioallantoic blood vessels of male and female placenta alters differentiation of female genital organs (the critical period of sexual differentiation is between 40 and 50 days of gestation in cows) .
  4. 4. 3-Ovarian functional alterations precede morphological changes owing to marked elevation of androstenedione concentration in the serum of the female embryo as early as 40 days of gestation. 4-These initial changes are followed by elevated concentrations of testosterone and androstenedione in the gonads of the female fetus by 75 days of gestation. 5-Testicular cords and cells resembling testicular interstitial cells are then developed in the ovary of the female fetus by 70 days of gestation.
  5. 5. 6-Cellular exchange between male and female fetuses results in development of chimaeras (having XX/XY cells due to vascular anastomosis). 7-Developmental abnormalities and degree of musculinization in the genital system of freemartins varies from animal to animal. It depend upon the developmental stage of the conceptus at the time of anastomosis, degree of anastomosis, amount and duration of inhibitors interchange ( ??? ).
  6. 6. Symptoms and clinical findings: 1-Freemartins are phenotypically steer like in appearance and never come in heat despite passing age of puberty (ox horn, massive shoulder, high limbs, narrow pelvis, small narrow vulva, large prominent clitoris, prominent tuft of coarse hair arises from the ventral vulval commissure, and the udder is underdeveloped with small rudimentary teats). 2-Clinical examination reveals that the measurements of all reproductive organs are markedly decreased (size and weight).
  7. 7. 3-The length of both vagina and vulva is markedly decreases (6-8 cm) and reveals blind vestibule as detected by Fincher pencil test or glass pipette. 4-Gonads are either aplastic or hypoplastic and detected as firm nodular structure. 5-Uterus, uterine horns, cervix, and anterior vagina are firm and uncanalized (can be detected as cord like structures). 6-Testicular structure and male accessory glands (Seminal gland) can also be detected in some cases.
  8. 8. Diagnosis: Phenotypic appearance is a steer like
  9. 9. Application of Fincher pencil test reveals blind vestibule enlarged clitoris
  10. 10. Seminal gland Redumented uterus vagina ovary testis clitoris cervix epididymis Colliculus seminalis Subnormal decrease in all measurements of the genitalia
  11. 11. Clinical significance and economic importance: 1-Increased incidence of twinning pregnancy increased the possibilities of freemartinism. 2-Increased incidence of freemartinism increases the number of sterile heifers and increases incidence of anestum in the herd that reduces fertility of the farm. 3-Freemartin should be fattened and slaughtered. 4-Females giving twin births should controlled and their offsprigs should be sexually examined.
  12. 12. 2-Hermaphrodites Hermaphrodite is a term applied to individuals whose genital organs exhibiting both sexes. Hermaphroditism has been recorded in all animal species, but with high frequency in goats (6 -14.9 %) and pigs. Hermaphroditism in goats caused by an autosomal recessive gene linked to an autosomal dominant gene for polledness or hornlessness. This gene have variable penetrations, and be responsible for sex reversal of genetic females to phenotypic males (because all hermaphrodites are genetically females, 60 XX kariotype) .
  13. 13. Classification of hermaphrodites: They are classified according to the dominating genital organs into: 1- True hermaphrodites ( low incidence): A-Bilateral (4gonads, TTOO, OOTT, TOOT, OT TO). B-Unilateral (3 gonads, TO O, TO T). C-Lateral (2 gonads, T O). 2-Pseudo-hermaphrodites (high incidence): A-Male pseudo-hermaphrodites. B-Female pseudo-hermaphrodites.
  14. 14. Morphological features of masculine type male pseudohermaphrodite kids: 1-Pseudohermaphrodites Kids are hornless, and develops an abnormal pouch at the terminal part of urethra that filled with urine. 2-Such a condition suffer urine incontinence that was treated by surgical dilatation of the external urethral orifice. 3-External genitalia revealed absence of scrotum, the penis is abnormally short, and the external urethral orifice open just cranial to the ischial arch.
  15. 15. Hornless mother Male pseudohermaphrodite kid male female
  16. 16. Morphological features of pseudohermaphrodites: 1-Older cases are hornless and exhibiting either masculine or feminine appearance. 2-The external genitalia consists of small subcutaneously located testes and the scrotum is seldom developed. 3-The penis is short and exhibits no sigmoid flexure. 4-the free end of the penis is bent upwards that makes urine stream directed upwards.
  17. 17. Masculine type malepseudohermaphrodite
  18. 18. Masculine type male pseudohermaphrodite
  19. 19. Feminine type male pseudohermaphrodite
  20. 20. A, testis. B, uterus and ductus deference. C, urinary bladder. D, hypospadias penis.

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