Chromosome Anomalies & Genetic Diseases

Basic Human Genetics – Mange Medical Cell Biology – Alan Goodman

Basic Human Genetics Mange Cell Biology Alan Goodman

Chromosome Anomalies & Genetic Diseases A. results from abnormal sex cell formation B. absence of an autosome C. absence of a sex chromosome ex. Turner’s syndrome D. Presence of an extra autosome ex. Down’s Syndrome

D. Presence of an extra autosome ex. Down’s Syndrome 1. open mouth with protruding tongue 2. straight hair 3. short, stocky build 4. mental retardation

E. Presence of an extra sex chromosome ex. Kleinfelter’s syndrome F. Genetic Screening 1. amniocentesis – old method 2. chorionic villus sampling – new method 3. karyotype – chromosome analysis

Amniocentesis is a test you may be offered during pregnancy to check if your baby has a genetic or chromosomal condition, such as Down's.

During the test, a long, thin needle is inserted through your abdominal wall, guided by an ultrasound image. The needle is passed into the amniotic sac that surrounds the fetus and a small sample of amniotic fluid is removed for analysis.

Chorionic villus sampling (CVS) is a prenatal test in which a sample of chorionic villi is removed from the placenta for testing. The sample can be taken through the cervix (transcervical) or the abdominal wall (transabdominal).

During pregnancy, the placenta provides oxygen and nutrients to the growing baby and removes waste products from the baby's blood. The chorionic villi are wispy projections of placental tissue that share the baby's genetic makeup.

Umbilical cord – made up of baby’s cells - that is why nowadays, in advanced hospitals they would ask if you would like to cryogenically store the umbilical cord because it contains the embryonic stem cells of your body We can do karyotyping (chromosome analysis) of fetal cells to test for Down’s syndrome, Turner’s syndrome

DNA analysis can test for sickle-cell anemia Down’s syndrome – most common chromosome anomaly - unfortunately nothing can be done because the defect is in every single cell of the body

The vast majority of times meiosis occurs perfectly but sometimes error may occur in the forming of eggs or sperm

Women have to be more protective of their bodies A woman’s egg is as old as she is

For the past 35-40 years, there was an international effort led by the USA to map the genes of the human body