Genetic DisordersAutosomal and Sex-linked

HOW DO WE GET GENETIC DISORDERS?

Nondisjunction – failure of chromosomes to separate during cell division. Results in too many or too few chromosomes.

KARYOTYPE -

Chart that shows the size, number, and shape of all chromosomes in an organism.

Patau syndrome, trisomy 13

1:5000 live births.

Lifespan – about a few months

Complications include: congenital heart disease, lack of breathing, deafness, feeding problems, heart failure, seizures, vision problems.

Edwards syndrome, trisomy 18

Lifespan – Most pass in first month, about 10% live past first year.

NOT inherited.Complications

include: low birth weight, small head, heart defects, organ abnormalities, fists with overlapping fingers.

Down’s syndrome, trisomy 21

Affects 1:700 children Lifespan – Usually to

adults, but shorter lifespan overall.

Complications include: characteristic facial features, short stature, heart defects respiratory disease, Alzheimer’s and leukemia, often sterile, mental retardation.

More prevalent with older mothers. Can be due to nondisjunction of father’s chromosome 21.

Cri-du-chat, deletion in 5

Abnormal rate of growth of the larynx (cry of the cat).

More common in females by 3:1 ratio.

Lifespan – generally normal

Complications include: microcephaly (small head), slow development, poor muscle tone, congenital heart defect, mental retardation.

Jacobs, XYY

All male. Affected – 1:1000

males have XYY.Complications

include: some taller, risk of learning disabilities, delayed language skills, behavioral problems.

Most males able to conceive children!

Turner’s, X0

Lifespan – slightly reduced

1:2500 females.Complications

include: short, broad chest, low hairline, reproductively sterile, obesity, small fingernails

Klinefelter’s, XXY

Affects 1:750 malesLifespan – normal.Underdiagnosed.Complications

include: low testosterone, less body hair/less muscular as teenager, often taller. More likely to get breast cancer, autoimmune disorders, and osteoporosis.

Triple X, XXX

The one to get!Affects 1:1000

femalesLifespan – NormalNo complications!

Fertile and healthy. Cannot tell

difference between Triple X and normal female.

Philadelphia translocation, 9 to 22 translocation

Affects - 1-2:10,000 newborns

Specific chromosomal abnormality that is associated with chronic myelogenous leukemia (CML).

95% of people with CML have this abnormality.

USEFUL WEBSITE:

http://www.hudsonalpha.org/education/kits/disorder-detectives/genetic-disorders