Chapter 6: Pedigree Analysis, Applications, And Genetic Testing

Front 1

Pedigree

Back 1

Pictorial representation of a family history outlining the inheritance of one or more traits or diseases.

Front 2

Proband

Back 2

A person having a trait or disease for whom a pedigree is constructed.

Front 3

Consanguinity

Back 3

Mating between related individuals.

Front 4

Dizygotic Twins

Back 4

Nonidentical twins that arise when two different eggs are fertilized by two different sperm; also called fraternal twins.

Front 5

Monozygotic Twins

Back 5

Identical twins that arise when a single egg fertilized by a single sperm splits into two separate embryos.

Front 6

Concordance

Back 6

Percentage of twin pairs in which both twins have a particular trait.

Front 7

Genetic Counseling

Back 7

Educational process that attempts to help patients and family members deal with all aspects of a genetic condition.

Front 8

Ultrasonography

Back 8

Procedure for visualizing the fetus. High-frequency sound is beamed into the uterus. Sound waves that encounter dense tissue bounce back and are transformed into a picture of the fetus.

Front 9

Amniocentesis

Back 9

Procedure used for prenatal genetic testing to obtain a sample of amniotic fluid from a pregnant woman. A long sterile needle is inserted through the abdominal wall into the amniotic sac to obtain the fluid.

Front 10

Chorionic Villus Screening

Back 10

Procedure used for prenatal genetic testing in which a small piece of the chorion (the outer layer of the placenta) is removed from a pregnant woman. A catheter is inserted through the vagina and cervix into the uterus. Suction is then applied to remove the sample.

Front 11

Karyotype

Back 11

Picture of an individual organism’s complete set of metaphase chromosomes.

Front 12

Maternal Blood Screening Test

Back 12

Tests for genetic conditions in a fetus by analyzing the blood of the mother. For example, the level of Α-fetoprotein in maternal blood provides information about the probability that a fetus has a neural-tube defect.

Front 13

Fetal Cell Sorting

Back 13

Separation of fetal cells from maternal blood. Genetic testing on the fetal cells can provide information about genetic diseases and disorders in the fetus.

Front 14

Preimplantation Genetic Diagnosis

Back 14

Genetic testing on an embryo produced by in vitro fertilization before implantation of the embryo in the uterus.

Front 15

Newborn Screening

Back 15

Tests newborn infants for certain genetic disorders.

Front 16

Presymptomatic Genetic Testing

Back 16

Tests people to determine whether they have inherited a disease-causing gene before the symptoms of the disease have appeared.

Front 17

Heterozygote Screening

Back 17

Tests members of a population to identify heterozygous carriers of a disease-causing allele who are healthy but have the potential to produce children who have the disease.

Front 18

Direct-To-Consumer Genetic Test

Back 18

Test for a genetic condition; the test can be purchased directly by a consumer, without the involvement of a physician or other health care provider.

Front 19

Genetic Information Nondiscrimination Act (GINA)

Back 19

U.S. law prohibiting health insurers from using genetic information to make decisions about health-insurance coverage and rates; prevents employers from using genetic information in employment decisions; also prevents health insurers and employers from asking or requiring a person to take a genetic test.