down syndrome ( trisomy 21)
DESCRIPTION
Down Syndrome ( trisomy 21). result of an extra chromosome 21 1:700 children characteristic facial features, short stature; heart defects, shorter lifespan… etc. has been correlated to the age of the mother but can also be result of nondisjunction of father’s chromosome 21. Down Syndrome. - PowerPoint PPT PresentationTRANSCRIPT
Down Syndrome (trisomy 21)• result of an extra
chromosome 21• 1:700 children• characteristic facial features,
short stature; heart defects, shorter lifespan… etc.
• has been correlated to the age of the mother but can also be result of nondisjunction of father’s chromosome 21
Down Syndrome
Patau Syndrome (trisomy 13)
• serious eye, brain, circulatory defects as well as cleft palate
• 1:5000• children rarely live more
than a few months
Klinefelter syndrome: XXY
• 47 chromosomes• affects the
sexual/gender specific characteristics
• Usually male sex organs with other female body characteristics
• Normal intelligence
Jacob’s Syndrome
• XYY males• individuals taller than
average, often with below normal intelligence
Trisomy X
• XXX metafemales• 1:1000 live births• healthy and fertile• usually cannot be
distinguished from normal female except by karyotype
Monosomy X – Turner’s Syndrome• Only one sex chromosome – X• 1:5000 • Only monosomy that will
produce viable offspring in humans
• Only have 45 chromosomes• Do not mature sexually during
puberty and are sterile (cannot reproduce)
• Short stature and normal intelligence
• 98% of these fetuses die