Example of Sex Chromosome Disorders -Turner's syndrome, Klinefelter's syndrome, Super males and Super females

Anomalies in Sex chromosomes
Turner's syndrome
  • Due to monosomy (2n-1)
  • The individual has 2n=45 chromosomes (44+X), instead of 46.
  • One in every 3000 females birth is a victim
Turner's syndrome Karyotype
  • Such persons are sterile females who have rudimentary ovaries, undeveloped breasts, small uterus, puffy fingers, short stature (less than 5 feet), webbed neck, abnormal intelligence, cardiovascular abnormalities and hearing impairment.
Klinefelter's syndrome
  • Is due to trisomy of sex X chromosome
  • Individual has47 chromosome (44+XXY).Such persons are sterile males  with undeveloped testes, mental retardation, long limbs and with some female  characteristics such as feminine pitched voice and enlarged breasts (Gynaecomastia)
  • One in every 500 male births is the victim of this syndrome.
  Super males
  • Such individuals have 47 (44+XYY) chromosomes. Characterized by abnormal height, mental retardation and criminal bent of mind (Jacob’s syndrome or Criminal syndrome)
  • Due to the over production of male sex hormones
  • Frequency is 1 in 1000.
Super females
  • Such individual have 47(44+XXX), 48(44+XXXX), or 49(44+XXXXX), chromosomes.
  • These females are characterised by abnormal sexual development and mental retardation.
  • The number of barr bodies is less than total number of X-chromosomes.
  • The frequency at birth of 44+XXX is 1 in 1500
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