Human Genetic Disorders

1
Human Genetic Disorders
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Autosomal genetic disorders

• The majority of genes are autosomal
• Therefore the majority of disorders are autosomal
• Examples
• Albinism (recessive C11)
• Cystic fibrosis (recessive C7)
• Tay Sachs (recessive)
• Sickle cell anemia (recessive)
• PKU (recessive)
• Huntingtons disease (dominant C4)

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Chromosome number disorder

• Nondisjunction
• Turner syndrome
• N-DJ of the sex chromosomes egg or sperm is
  produced with no sex chromosome
• Individual is 45 XO
• Klinefelter syndrome
• NDJ results in cells with an extra sex chromosome
• Individual is 47 XXY
• Down syndrome
• NDJ of autosome
• Individual has three copies of C21

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Other mechanisms and analysis

• Chromosome deletions and translocations
•  Prenatal diagnosis
• Amniocentesis
• Chorionic villus sampling
• Genetic counseling