NORMAL KARYOTYPE

What is wrong with this karyotype?

Down Syndrome• Occurs in 1 of every 800 births• Slanting eyes with folds of skin

at the inner corners• Short neck, small head, small

oral cavity (mouth)• Smaller, poor muscle tone,

hyperflexibility of joints• Some degree of mental

retardation

Turner Syndrome• XO female

(no “Y” means - not a guy)

• 1 in every 2000 births

• Short stature, lack of ovarian development (infertile), and folds of skin on the neck are common.

• Arms that turn out at the elbow and a low hairline along the back of the neck are also seen.

Klinefelter Syndrome • Are males

because they are XXY

• 1 out of every 500-1000 births

• Often tall, but not always “in proportion”

• Fail to develop normal secondary sex characteristics

• Often have learning disabilities

• Often have gynecomastia

• Nondisjunction of sex chromosomes - monosomy (XO)- trisomy (XXY, XXX, XYY)

• Nondisjunction of autosomal chromosomes- only trisomy 21 is usually not fatal

- trisomy 13 and trisomy 18 may survive up to a year after birth