genetic disorder

• Genetic disorder


  An illness caused by one or more abnormalities in the genome, especially a condition that is present from birth (congenital)
• Most genetic disorders are quite rare and affect one person in every several thousands or millions
• Heritable genetic disorder


  Genetic disorder that is passed down from the parents' genes
• Non-heritable genetic disorder


  Genetic disorder caused by new mutations or changes to the DNA, not passed down from parents
• Gregor Mendel studied inherited characteristics


  1866
• Discovery of DNA structure by Wilkins, Franklin, Crick and Watson


  1950s
• Arthur Kornberg produced DNA in a test tube


  1957
• The Genetic code was discovered

  1966
• Barbara McClintock discovered genes can change position on chromosomes


  1983
• International team began project to map the human genome

  Late 1980s
• First use of gene therapy for a patient

  1990
• Earliest evidence of hereditary genetic disorder discovered is a 1.5 million year old Homo erectus fossil
• Classification of genetic disorders

  • Single gene disorder
  • Chromosomal genetic disorder
  • Multifactorial genetic disorder
• Single gene disorder


  • Mutations in the DNA sequences of single genes, resulting in altered or missing proteins
• Single gene disorders


  • Adenosine deaminase deficiency
  • Alpha-1 Antitrypsine deficiency
  • Cystic fibrosis
  • Galatosemia
  • Huntington's disease
  • Maple syrup urine disease
  • Phenylketonurimea
  • Severe combined immunodeficiency
  • Sickle cell disease
  • Smith-Lemil-Optiz Syndrome
• Cystic fibrosis


  Genetic disorder affecting the respiratory and digestive systems, caused by a defective CFTR gene on chromosome 7
• Galactosemia


  Rare disorder affecting the body's ability to break down the food sugar galactose, caused by a deficiency in the GALT enzyme
• Severe Combined Immunodeficiency (SCID)

  Inherited disorder related to the immune system, caused by a mutation in the SCIDX1 gene on the X chromosome
• Sickle cell disease


  Disorder affecting red blood cells, caused by a mutation in the gene on chromosome 11 that codes for the beta subunit of hemoglobin
• Fibrodysplasia Ossificans Progressiva (FOP) is an extremely rare genetic disease that causes soft tissue to turn into bone
• Chromosomal genetic disorder


  • Entire chromosomes or large segments are missing, duplicated, or otherwise altered
• Types of chromosomal genetic disorders

  • Numerical abnormalities (monosomy, trisomy)
  • Structural abnormalities
• Chromosomal genetic disorders


  • Cri-Du-Chat Syndrome
  • Down Syndrome
  • 47 XXY Klinefelter Syndrome
  • Turner Syndrome
  • William Syndrome
• Cri-du-chat syndrome


  Caused by a deletion on the short arm of chromosome 5, resulting in abnormal larynx development and a distinctive "cat-like" cry
• Down syndrome


  Caused by an extra copy of chromosome 21, resulting in developmental delays and increased risk of medical problems
• Klinefelter syndrome (47, XXY)


  Caused by the presence of two X chromosomes and one Y chromosome, resulting in incomplete sexual development in males
• Turner syndrome


  Caused by a missing or incomplete X chromosome, resulting in short stature and abnormal sexual development in females
• Williams syndrome


  Rare genetic disorder affecting growth, physical appearance, and cognitive development, caused by missing genetic material from chromosome 7
• Colorblindness


  Caused by mutated genes located on the X chromosome (for red/green color blindness) or both the X and Y chromosomes (for total color blindness)
• Multifactorial disorder


  Disorders involving variations in multiple genes, often coupled with environmental causes
• Alzheimer's disease


  A disease that causes dementia, characterized by abnormal clumps of cellular debris and protein (plaques) and collapsed microtubules (tangles) that damage healthy brain cells