Question

H estments Help Save & Exit Methods of obtaining DNA Before karyotypes are created, DNA must be obtained. Group the following statements to describe the different methods available for obtaining fetal DNA for genetic testing. Answer choices may be used more than once. Amniocentesis Cells obtained have DNA that is used for genetic testing ances Cells are removed from the chorion Cells are removed from amniotic Huid Chorionic Villus Sampling (CVS) A needle is inserted through the abdomen 6 Next >

Answer 1

Aminocentesis-

The procedure involves the insertion of a needle into the womb and drawing out approximately 10cc of amniotic fluid.

Then cell are removed from the amniotic fluid .The amniotic fluid, which contains cells shed by the fetus, is sent to the laboratory for analysis.

Cell obtained have DNA that is used for genetic testing - In this procedure, a small amount of amniotic fluid, which contains fetal tissues, is sampled from the amniotic sac surrounding a developing fetus. The fetal DNA is then examined for genetic abnormalities. It is also used for prenatal genetic diagnosis, fetal cells are separated from the extracted sample. The cells are grown in a culture medium, then fixed and stained. Under a microscope the chromosomes are examined for abnormalities. The most common abnormalities detected are Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Turner syndrome (monosomy X). The sample is also analyzed for fetal infection and for intra-amniotic inflammation through infection studies

Choronic villi Sampling (CVS)

Needle is inserted through abdomen .

CVS can be done through the cervix (transcervical) or through the belly (transabdominal). Miscarriage rates are slightly higher when the test is done through the cervix.

The transcervical procedure is performed by inserting a thin plastic tube through the vag*na and cervix to reach the placenta. Your health care provider uses ultrasound images to help guide the tube into the best area for sampling. A small sample of chorionic villus (placental) tissue is then removed.

The transabdominal procedure is performed by inserting a needle through the abdomen and uterus and into the placenta. Ultrasound is used to help guide the needle, and a small amount of tissue is drawn into the syringe.

Cells are removed from chorion

It entails sampling of the chorionic villus (placental tissue) and testing it for chromosomal abnormalities, usually with FISH or PCR. CVS usually takes place at 10–12 weeks'. It take same process of aminocentesis in 2nd step