Ch. 6

proband

An affected person in a family pedigree who brings the family to the attention of the medical community

concordance

agreement or harmony

chronic villus sampling (CVS)

biochem analysis on fetal cells 10th-12th week in vitro karyotype from fetal cells complicated

direct-to-consumer genetic testing

genetic test that can be purchased without the involvement of a health professional

monozygotic twins

identical twins formed when one zygote splits into two separate masses of cells, each of which develops into a separate embryo

discordant

lacking harmony or agreement

dizygotic twins

often called fraternal twins, occurring when two eggs each get fertilized by two different sperm, resulting in two zygotes in the uterus at the same time

neural tube deffect

shown as higher alpha-fetoprotien levels in mothers blood