Prenatal diagnosis: Trisomy 21 (Down’s syndrome) karyotype picture of the chromosomes in a cell...

Prenatal diagnosis: Trisomy 21 (Down’s syndrome)

karyotype• picture of the chromosomes in a cell used to check for abnormalities

Preparing a karyotype

• harvest cells

Postnatal diagnostic karyotype tumor biopsy skin cells from mouth (ie. for non-cancer related diagnoses)

Prenatal diagnostic karyotypechorionic villi sampling (CVS)amniocentesis

Who is offered amniocentesis or CVS?

• maternal age (women 35 or older)Risk of Down’s syndrome: mother in 20s 1/1250 99.92% OKmother at 35 1/400 99.75% OKmother at 40 1/100 99% OK

Prenatal diagnosis: amniocentesis

• sampling cells from amniotic fluid• usually done ~ 15-18 weeks

DiGeorge syndrome/CATCH22

• microdeletion on chromosome 22• birth defect that affects the immune system• absence of or underdevelopment of the thymus and parathyroid glands• facial features include low-set ears, wide-set eyes, small

jaw, and bowing up of upper lip

EngageGenetic Disorders

• Patau Syndrome

• Edward Syndrome

• Klinfelter’s Syndrome

• Turner Syndrome

• Super Male Syndrome

• Super Female Syndrome

47, XX or XY, +13

• serious eye, brain, circulatory defects as well as cleft palate. 1:5000 live births. Children rarely live more than a few months.

• Patau Syndrome

Edward Syndrome

• almost every organ system affected 1:10,000 live births. Children with full Trisomy 18 generally do not

live more than a few months.

Turner Syndrome

Turner Syndrom

Kleinfelter Disease

Kleinfelter

Super Male and Super Female

• - Has an XXX- Fertile females with normal intelligence

Has an XYYHas an XYY- Tall male with heavy acne- Tall male with heavy acne- Some tendency to mental - Some tendency to mental retardationretardationAggressive tendencyAggressive tendency