Human Chromosome Disorders

Karyotype—Map of Human Chromosomes Homologue

Chromosome disorders Sometimes meiosis goes wrong Most of the time, the pregnancy ends naturally because most chromosome disorders are lethal Extra chromosome = trisomy

21 trisomy – Downs Syndrome Can you see the extra 21 st chromosome? Is this person male or female?

Down’s syndrome *A flattened appearance to the face *An upward slant to the eyes * Short neck, arms and legs *Intellectual disability *Extra friendly and outgoing

Edward’s syndrome-trisomy 18 Clenched hands Crossed legs Feet with a rounded bottom (rocker-bottom feet) Mental deficiency Small head

Patau syndrome Trisomy 13

Turner’s syndrome—the only case of missing a chromosome that can be survived Females who are XO instead of XX Stocky appearance, arms that turn out slightly at the elbow, a receding lower jaw, a short webbed neck. Other medical symptoms include: heart and/or kidney defects, high blood pressure, and infertility (inability to have children).

What if a karyotype showed you would have a child with a chromosomal abnormality? What would you do?