embryo biopsy definition of embryo biopsy in the Free Online Encyclopedia.

embryo biopsy or preimplantation genetic diagnosis (PGD), diagnostic procedure, used in genetic screening genetic screening, testing for genetic disorders. Most commonly, prospective parents or an embryo or fetus is tested when a specific genetic disorder is suspected (e.g., Tay-Sachs or sickle cell disease).
..... Click the link for more information. , in which a single cell is removed from an embryo two or three days after it has been conceived through in vitro fertilization in vitro fertilization , technique for conception of a human embryo outside the mother's body. Several ova, or eggs, are removed from the mother's body and placed in special laboratory culture dishes (Petri dishes); sperm from the father are then added, or in many
..... Click the link for more information. . At this age the embryo consists of about eight genetically identical cells. The embryo itself is unaffected and continues to grow while the selected cell's genes are replicated using polymerase chain reaction polymerase chain reaction (PCR), laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sample of a piece of DNA; the process is sometimes called DNA amplification.
..... Click the link for more information. and then studied for genetic defects. The procedure allows an embryo to be tested before it is implanted into the womb when an inheritable disease or a genetic predisposition to a disease is carried by or exhibited in one or both parents.

Embryo biopsy has been used successfully to screen for such diseases as cystic fibrosis cystic fibrosis , inherited disorder of the exocrine glands (see gland), affecting children and young people; median survival is 25 years in females and 30 years in males.
..... Click the link for more information. and Tay-Sachs Tay-Sachs disease , rare hereditary disease caused by a genetic mutation that leaves the body unable to produce an enzyme necessary for fat metabolism in nerve cells, producing central nervous system degeneration.
..... Click the link for more information. as well as for genes that predispose a person to breast or colon cancer. The procedure can also be used to determine the gender of the embryo. Given this ability, X-chromosome-linked diseases that manifest only in males (hemophilia hemophilia , genetic disease in which the clotting ability of the blood is impaired and excessive bleeding results. The disease is transmitted through females but almost invariably affects male offspring only.
..... Click the link for more information. , for example) can be "screened" by implanting only female embryos (which will carry but will not develop the disease). Another variation, used for women over 35 (women past that age being statistically more likely to give birth to babies with Down syndrome Down syndrome, congenital disorder characterized by mild to severe mental retardation, slow physical development, and characteristic physical features. Down syndrome affects about 1 in every 730 live births and occurs in all populations equally.
..... Click the link for more information. and other chromosomal defects) involves examining the sample to make sure it has the correct number of chromosomes. Embryo biopsy has also been used to select a child who is a compatible donor for a sibling with a life-threatening disease such as certain anemias and leukemias.

See also amniocentesis amniocentesis , diagnostic procedure in which a sample of the amniotic fluid surrounding a fetus is removed from the uterus by means of a fine needle inserted through the abdomen of the pregnant woman (see pregnancy).
..... Click the link for more information. ; birth defects birth defects, abnormalities in physical or mental structure or function that are present at birth. They range from minor to seriously deforming or life-threatening. A major defect of some type occurs in approximately 3% of all births.
..... Click the link for more information. ; chorionic villus sampling chorionic villus sampling (CVS) or chorionic villus biopsy (CVB) , diagnostic procedure in which a sample of chorionic villi from the developing placenta is removed from the uterus of a pregnant woman (see pregnancy) using a fine needle inserted
..... Click the link for more information. .

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No references found			The plan also calls for aggressively pursuing an assessment of the potential of alternative sources of pluripotent stem cell lines, including altered nuclear transfer; single cell embryo biopsy, and reprogramming, or dedifferentiation of somatic cells, such as skin cells. President orders NIH to explore expanding pluripotent stem cell lines by Transplant News At that point, doctors use a laser to make a hole in the envelope surrounding the embryo and, with a pair of tiny pipettes, remove one cell in a procedure known as embryo biopsy. Born to heal: screening embryos to treat siblings raises hopes, ... by Harder, Ben / Science News Research has shown the ZILOS-tk[R] to be beneficial to the IVF clinic in terms of embryo safety, procedure speed, and simplification of the embryo biopsy process. Hamilton Thorne Biosciences Announces Third-round FDA Marketing ... by Business Wire			embolite Embolomeri Embolotherium embolus emboly emboss embossed plate printer embosser Embossing embossing die Embossing Press embossing stylus embouchure embow embowed embrasure embrechites Embrithopoda Embritopoda embrittlement embrocation Embroidering Machine Embroidery embryo Embryo Adaptation embryo biopsy embryo rescue Embryo Sac Embryobionta embryogenesis embryoid Embryology Embryology, Experimental Embryology, Plant embryoma of the ovary embryonal-cell lipoma embryonate embryonated egg culture embryonic Embryonic Development embryonic differentiation embryonic inducer embryonic induction Embryonic Similarity embryonic stem cell Embryopathy Embryophyta Embryotomy EMC EMD Enterprises, Inc. Emden			Embrothel Embroude embrown embrowned embrowning embrowns EMBRS EMBRU embrue embrue embrued embrues embruing Embrujada embrujados Embrute Embry Call Embry-Riddle Aeronautical University Embry-Riddle Language Institute embryatrics embryectomies embryectomies embryectomy embryectomy embryo embryo embryo embryo Embryo Adaptation Embryo Associated Immunosuppressor Factor embryo biopsy embryo collection embryo collection embryo collection embryo collection Embryo Containing the Information of the Whole Organism embryo cryopreservation embryo cryopreservation embryo cryopreservation embryo cryopreservation Embryo Fibroblast Line embryo hatching embryo implantation embryo implantation embryo implantation Embryo Infectious Dose Embryo Lethal Dose embryo micromanipulation embryo micromanipulation embryo micromanipulation embryo micromanipulation embryo rescue embryo sac embryo sac embryo sac embryo transfer embryo transfer embryo transfer embryo transfer embryo transfer embryo transplant