down syndrome have 3 copies of chromosome # 21 (trisomy) nondisjunction genetic disorder symptoms...
Post on 02-Jan-2016
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Down Syndrome
• Have 3 copies of chromosome # 21 (trisomy)
• Nondisjunction genetic disorder
• Symptoms include cognitive delays, eyes that slant upward and heart defects
• Affects over 350,000 people in the U.S.
• No cure or treatment
Turner Syndrome• Have only one X
chromosome (monosomy)• Nondisjunction genetic
disorder• Symptoms include short
stauture, lack of ovariam development, webbed neck, arms that turn out, & low hairline in the back of the head.
• Affects 60,000 girls and women in the U.S.
• No cure or treatment
Klinefelter Syndrome• Have a Y & 2 X
chromosome (trisomy)• Nondisjunction genetic
disorder• Symptoms include males
that do not develop secondary sex characteristics such as facial hair & underarm hair.
• Affects 1 in 500 to 1 in 1000 male births in the U.S.
• No cure or treatment
Huntington’s Disease• Genetic mutation of a
normal gene in brain cells• Dominant genetic disorder• Symptoms include
uncontrolled movements, loss of intellectual faculties, & emotional disturbance
• Affects 1 in 10,000 in the U.S.
• Medications can be prescribed to help control emotional & movement
Normal Brain
Huntington’s Disease
Achondroplasia
• Faulty gene that is involved in bone growth
• Dominant genetic disorder
• Symptoms include short stature (problems with growth & development of the skeleton)
• Affects 1 in 20,000 births in the U.S.
• No cure or treatment
Albinism• Have little or no pigment
(melanin) in their eyes, skin, or hair
• Recessive genetic disorder• Symptoms include red
eyes, vision problems, & very light skin & hair.
• Affects 1 in 17,000 births in the U.S.
• Treatment: – Eye condition - surgery,
glasses, contact lenses– Skin - use UV skin protection
Tay Sachs Disease• Fatal genetic lipid storage
disorder where fatty substances build up in nerve cells in the brain
• Recessive genetic disorder• Symptoms include
deterioration of mental & physical abilities (blind, deaf, unable to swallow, muscle atrophy)
• Very rare - 1 in 27 people are carriers (Ashkenazi Jews) & 1 in 250 people are carriers (general population).
• No cure or treatment
Cystic Fibrosis• Approx. 30,000 people in US have
CF• Excessive mucus production• Defective CF gene produces
abnormally thick and sticky mucus• Digestive & respiratory failure• Recessive genetic disorder• Coughing or increased mucus in the
sinuses or lungs• Fatigue & Weight loss• Nausea and loss of appetite• No cure• Daily cleaning of mucus from lungs• Take mucus thinning drugs
Hemophilia• Mutation of genes for the
blood clotting factors on the X chromosome
• Sex-linked trait• Symptoms include bleeding
continuously until they are treated - blood does not clot.
• Affects about 18,000 people in U.S. (affects more men than women because women are more likely to be carriers)
• No cure or treatment
Color Blindness• Mutation of genes on the
X chromosome• Sex-linked trait• Symptoms include not
being able to identify any color or difficulty in telling different shades of color apart.
• Affects 8% of men & 1% of women (women are more likely to be carriers)
• No cure or treatment
Red-green color blindness – recessive and linked to the X chromosome
XC = Colorblind alleleXN = Normal allele
XNXN = Normal sightXNXC = Carrier for colorblindnessXCXC = ColorblindXCY = Colorblind
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