All Clinical Services
Preimplantation genetic diagnosis (PGD) is a screening test used to determine if genetic or chromosomal disorders are present in embryos produced through in vitro fertilization (IVF). Preimplantation genetic diagnosis screens embryos before they are transferred to the uterus so couples can make informed decisions about their next steps in the IVF process. Embryos unaffected by the genetic or chromosomal disorder can be selected for transfer to the uterus.
For couples undergoing IVF, preimplantation genetic diagnosis may be recommended when:
Thousands of clinical preimplantation genetic diagnosis cycles have been performed worldwide, resulting in the birth of hundreds of healthy babies.
Preimplantation genetic diagnosis can be used to determine if embryos produced through in vitro fertilization carry a gene mutation associated with a specific genetic disorder, such as cystic fibrosis or muscular dystrophy.
The benefit of preimplantation genetic diagnosis is that the diagnosis can be made before the embryos are transferred to the uterus and a pregnancy is established. Embryos unaffected by the genetic disorder can be selected for transfer to the uterus, therefore greatly reducing the risk that a couple will pass a genetic disorder onto their child.
Couples who are at high risk of having a child with a severe genetic disorder may choose preimplantation genetic diagnosis for many reasons, including:
Preimplantation genetic diagnosis is also offered to couples when one partner has a chromosomal abnormality, such as an unbalanced translocation or anerplocity. If the abnormality is present in the embryo, the condition could ultimately prevent embryo implantation, lead to pregnancy loss, or result in the birth of a child with congenital malformations (physical problems) or mental retardation.
The benefit of preimplantation genetic diagnosis is that the diagnosis can be made before the embryos are transferred to the uterus and a pregnancy is established. Embryos unaffected by the chromosomal abnormality can be selected for transfer to the uterus, therefore greatly reducing the risk that the pregnancy will be adversely affected by the chromosomal abnormality.
Couples who are at high risk of having a child with a chromosomal disorder may choose preimplantation genetic diagnosis for many reasons, including:
Genetic counseling is an important step to determine if preimplantation genetic diagnosis is an appropriate option for a patient. Penn Fertility Care providers work closely with the genetic counselors in Penns Division of Reproductive Genetics. For couples undergoing IVF who are concerned that their child may inherit a genetic disorder or chromosomal abnormality, genetic counselors are available to discuss options and can advise patients on how raising a handicapped child may affect a family.
Learn more about Genetic Counseling services at Penn
Preimplantation genetic diagnosis is available for couples undergoing IVF. The steps of the IVF process include:
Embryo biopsy may be performed after 3 days of culture in the laboratory. The embryos are typically 8-cell embryos on Day-3 and the process involves the removal of one to two cells.
After the biopsy and following receipt of the results from the genetic/chromosomal testing, embryo(s) of the best quality that are not affected by the genetic disorder or chromosomal abnormality) are selected for transfer to the uterus. For day 3 embryo biopsies, the embryo is usually transferred "fresh" following two additional days of culture in the laboratory (Day-5 embryo transfer).
In some cases, the biopsy will be done on either Day-5 or -6 (trophectoderm biopsy). At this stage, the embryo consists of many cells and is called a blastocyst. Cells are removed from the outer layer of cells called the trophectoderm.
Following the biopsy of a good quality blastocyst, the blastocyst is then frozen. When the patient receives the results from the genetic testing, the non-affected or chromosomally normal blastocyst(s) are thawed and transferred in a subsequent frozen embryo cycle.
Embryos are analyzed by one of the techniques described below:
Polymerase Chain Reaction (PCR) is performed on the biopsied cell(s) to determine the presence of a single gene. This is done when a couple has a significantly increased risk of conceiving a child with a severe genetic disorder. When PCR is to be performed, the cell(s) obtained at biopsy is loaded into a tiny tube of medium and sent to for analysis. The specific area of DNA of interest is amplified by making thousands of copies of the DNA through repeated cycles of DNA strand separation and replication. The sample can be analyzed for the presence of a specific sequence of DNA or gene and also for linkage markers near the gene. The biopsied cell(s) are destroyed during this process. Therefore, they cannot be used for another purpose or returned to the embryo.
The genetic material (DNA) within the biopsied cell(s) is amplified using a technique called the polymerase chain reaction (PCR). This amplification produces enough DNA to use a second technique, known as array comparative genomic hybridization (aCGH). Array CGH assesses the amount of DNA derived from each chromosome, revealing whether or not there are both a normal amount and correct number of chromosomes. The biopsied cell(s) are destroyed during this process. Therefore, they cannot be used for another purpose or returned to the embryo. aCGH can be used to screen for numeric abnormalities in all chromosomes and/or known rearrangements of chromosomes (translocations). Array CGH does not detect all types of chromosome aberrations or genetic mutations and cannot distinguish between no translocation present and balanced translocation present.
The results of preimplantation genetic diagnosis are reported to the couple no later than the morning of their scheduled day for embryo transfer. Typically this is five days after oocyte retrieval and in vitro fertilization are performed. Of the embryo(s) that are not affected by the genetic disorder or chromosomal abnormality, the best quality embryo(s) are selected for transfer to the uterus. If additional unaffected and good-quality embryos are available, they may be cryopreserved for a future embryo transfer.
No, preimplantation genetic diagnosis does not replace prenatal testing, such as chorionic villus sampling or amniocentesis. Preimplantation genetic diagnosis provides diagnostic information based on the analysis of asinglecell. Therefore, prenatal testing is still recommended and currently remains the standard of care.
Learn more about prenatal testing services at Penn
For more information about preimplantation genetic diagnosis or to schedule an appointment with a Penn Fertility Care specialist, call 800-789-PENN (7366).
Need an appointment? Request one online 24 hours/day, 7 days/week or call 800-789-PENN (7366) to speak to a referral counselor.
Link:
preimplantation genetic diagnosis - Penn Medicine
- IOM not webcast today. Why Not? - November 8th, 2009 [November 8th, 2009]
- National Academies skeptical at Best. - November 8th, 2009 [November 8th, 2009]
- Some Confusion Exists - November 8th, 2009 [November 8th, 2009]
- Why DTC Genomics IS Medicine. - November 8th, 2009 [November 8th, 2009]
- First Mari, Now Linda. Who's next? - November 8th, 2009 [November 8th, 2009]
- Is it true? - November 8th, 2009 [November 8th, 2009]
- Re-Reviewing the National Academies - November 8th, 2009 [November 8th, 2009]
- The problem with nonclinicians....... - November 8th, 2009 [November 8th, 2009]
- Crazy Night of Emails to Government - November 8th, 2009 [November 8th, 2009]
- Adrienne Carlson's Personalized Medicine. - November 8th, 2009 [November 8th, 2009]
- Tell Me, How do you feel now? Sherpa's RX - November 8th, 2009 [November 8th, 2009]
- This Just In. 23andMe to go to GPs. I love my readers!! - November 8th, 2009 [November 8th, 2009]
- Sorry so long away - November 8th, 2009 [November 8th, 2009]
- 2D6 Rears its ugly head..... - November 8th, 2009 [November 8th, 2009]
- Ok, Fine, Back to Plavix - November 8th, 2009 [November 8th, 2009]
- Kaiser a protoype for Collins' Aim - November 8th, 2009 [November 8th, 2009]
- A few months late to the party.... - November 8th, 2009 [November 8th, 2009]
- Stated Another Way....... - November 8th, 2009 [November 8th, 2009]
- Excuse Me? Harvard and Navigenics? WTF? - November 8th, 2009 [November 8th, 2009]
- Follow up to Yesterday's WTF? Harvard, Navi? and Pfizer??? - November 8th, 2009 [November 8th, 2009]
- Did you get your kit? Thanks Dr. Rob from MedCo - November 8th, 2009 [November 8th, 2009]
- Gluco...Wha? Parkinson's Disease and Glucocerebrosidase mutations. - November 8th, 2009 [November 8th, 2009]
- Away and now back, What did I miss???? 23andme layoffs? Selling Genomes for cheap up next! - November 8th, 2009 [November 8th, 2009]
- Change IS Needed. I agree with William, sometimes. - November 8th, 2009 [November 8th, 2009]
- Good Enough Science? Apparently so at 23andme - November 8th, 2009 [November 8th, 2009]
- Long QT Syndrome, location matters - December 13th, 2009 [December 13th, 2009]
- Congratulations Generation Health. Nice pick up! - December 13th, 2009 [December 13th, 2009]
- An argument 23andSerge can't win...23andme but not medicine - December 13th, 2009 [December 13th, 2009]
- Stop. Breathe. Repeat. An analysis of the direction of DTC Genomics Field. - December 13th, 2009 [December 13th, 2009]
- Hey DTC genomics, Stay Private, Stay Alive, Go Public and Die - December 13th, 2009 [December 13th, 2009]
- You can't have it both way. Either scared your genome is sold off or not. - December 13th, 2009 [December 13th, 2009]
- 15 Days Away Gives Time for Perspective. - December 13th, 2009 [December 13th, 2009]
- What about the SACGHS registry? Another missed opportunity? - December 13th, 2009 [December 13th, 2009]
- AJHG is in and my Favorite Muin is in it! But He Is NOT the Father! - December 13th, 2009 [December 13th, 2009]
- Navigenics for 23andMe prices? - December 18th, 2009 [December 18th, 2009]
- Lp(a) Maybe there's something there that wasn't there before? - December 24th, 2009 [December 24th, 2009]
- Another Year, Another Bankruptcy - December 31st, 2009 [December 31st, 2009]
- 5 Technologies going bye bye in this decade? - January 6th, 2010 [January 6th, 2010]
- Hackers, HITECH and HIPAA in DTC Genomics, Oh My! - January 7th, 2010 [January 7th, 2010]
- Personal Genomics Flop.....big Belly Flop! - January 8th, 2010 [January 8th, 2010]
- Gotta Love It. Even the daycare....... - January 11th, 2010 [January 11th, 2010]
- Congratulations Navigenics. You ARE a clinical lab! Uh-Oh... - January 12th, 2010 [January 12th, 2010]
- CETP, Jewish Centenarians and Alzheimers - January 14th, 2010 [January 14th, 2010]
- Enter the "Not" DTC Genomics Rep - January 17th, 2010 [January 17th, 2010]
- Why Dr. Vanier's Navigenics appointment is good for PM - January 22nd, 2010 [January 22nd, 2010]
- Holy Crap! MedCo Follows in CVS footsteps - February 3rd, 2010 [February 3rd, 2010]
- FDA, Warfarin, still not as sexy to me. - February 5th, 2010 [February 5th, 2010]
- Hype, Hype, Hype from a single study. - February 11th, 2010 [February 11th, 2010]
- I love my readers, even Renata M! - February 17th, 2010 [February 17th, 2010]
- How can insurers use DTC genomics to profile? - February 17th, 2010 [February 17th, 2010]
- 9p21.....ahem. Paynter et.al. Smackdown. Again. - February 18th, 2010 [February 18th, 2010]
- Hey! It's Pete Hulick! Are you Going to GET? - February 19th, 2010 [February 19th, 2010]
- I was wrong......AHEM - February 28th, 2010 [February 28th, 2010]
- G2C2, finally a tool for genomic education! - March 2nd, 2010 [March 2nd, 2010]
- Just 4 million? What 23andMe is worth. - March 5th, 2010 [March 5th, 2010]
- What a difference a year makes - March 9th, 2010 [March 9th, 2010]
- ........DTC Genomic Medicine? - March 12th, 2010 [March 12th, 2010]
- The FDA, 2c19 and the ACC - March 13th, 2010 [March 13th, 2010]
- The problem with Comparative Whole Genomics...... - March 13th, 2010 [March 13th, 2010]
- BRCA testing by 23andME is the same as Myriad Genetics. - March 15th, 2010 [March 15th, 2010]
- The Argument Against DTC Genomics Marketing and such - March 16th, 2010 [March 16th, 2010]
- A moment of Clarity. Some DTCG is not bad. - March 18th, 2010 [March 18th, 2010]
- SNPs for breast cancer risk? It Depends. - March 18th, 2010 [March 18th, 2010]
- How can MDVIP use Navigenics Test for Medicine? - March 18th, 2010 [March 18th, 2010]
- Why did P&G invest in Navigenics? - March 23rd, 2010 [March 23rd, 2010]
- PGx in DTCG? Doesn't stand up to Useful testing. - March 25th, 2010 [March 25th, 2010]
- End of Gene Patents? - March 29th, 2010 [March 29th, 2010]
- Sherpa Accepting Chief Medical Officership - April 3rd, 2010 [April 3rd, 2010]
- The Rumors of My Death........ - April 20th, 2010 [April 20th, 2010]
- Happy DNA Day! - April 25th, 2010 [April 25th, 2010]
- 99 USD, DNA day and patient letters - April 25th, 2010 [April 25th, 2010]
- 2C19, Navigenics and Clinical Reality. - May 1st, 2010 [May 1st, 2010]
- Coriell Personalized Medicine Collaborative rising - May 7th, 2010 [May 7th, 2010]
- Personal Genomes in Clinical Care. Quake paper is a waste! - May 11th, 2010 [May 11th, 2010]
- Personal Genomes in Clinical Care. Quake paper Falls Short! - May 13th, 2010 [May 13th, 2010]
- Last post edited by Drew - May 13th, 2010 [May 13th, 2010]
- GateKeeper? FCUK U! - May 13th, 2010 [May 13th, 2010]
- GateKeeper? F! U! - May 15th, 2010 [May 15th, 2010]
- Potential of genomic medicine, LOST - May 19th, 2010 [May 19th, 2010]
- How Bad Can a House Investigation be for DTC Genomics? - May 20th, 2010 [May 20th, 2010]