About Careers MedBlog Contact us
Medindia LOGIN REGISTER
Advertisement

Preconception Diagnosis Procedure May Pose Health Risks

by Sheela Philomena on April 11, 2011 at 11:32 AM
Font : A-A+

 Preconception Diagnosis Procedure May Pose Health Risks

A procedure used in preconception diagnosis, that is used to identify eggs that are free of genetic disease can lead to some problems with pregnancy, says study.

Preimplantation genetic diagnosis (PGD) and preconception diagnosis (PCD) are services that have been very useful to couples who have a genetic defect in their family. "PGD and PCD represent alternatives to conventional prenatal diagnosis for couples who have a high risk of giving birth to a child affected with a serious genetic disorder and can prevent the anxiety associated with a prenatal diagnosis procedure and the optional termination of the pregnancy," explains lead study author Dr. Julie Steffann from the Universit Paris-Descartes and H'pital Necker-Enfants Malades in Paris, France. The processes involve performing genetic diagnostics on a cell removed from a developing embryo, in the case of PGD, or from a cell called a polar body, which supports the unfertilized egg, in the case of PCD. Those embryos and eggs that are found to be free of mutations are then considered safe to proceed with through pregnancy.

Advertisement

Dr. Steffann and colleagues Nadine Gigarel, and Jean-Paul Bonnefont, and Arnold Munnich from the Universit- Paris-Descartes and H'pital Necker-Enfants Malades and David Samuels from Vanderbilt University Medical Center in Nashville, TN show that assuming the polar body has a genetic make-up that matches that of the unfertilized egg can be complicated in some cases. The polar body divides from the egg when the egg develops, so it was thought that it could serve as a proxy for the egg and that testing it would allow a genetic diagnosis to be made without harming the egg. This is true for genes in the nuclear DNA, but the authors show that things are different for genes in the mitochondria.

If a person has a mutation in mitochondrial DNA, it can be present in all of the mitochondria or in a percentage of the mitochondria. This is referred to as mutant load. If the mutant load is high, the person can have the disease associated with that mutation, but if the mutant load is low enough, the person can be healthy. For these reasons, clinicians performing PCD want to select eggs with a low mutant load. In this work, Dr. Steffann and colleagues show that there is a poor correlation between the mutant load of mitochondrial DNA in an egg and that of its polar body. Finding a low mutant load in a polar body doesn't mean that the mutant load will be low in the associated egg; this could lead to incorrect conclusions regarding which eggs are safe to use for pregnancy.
Advertisement

"Our findings argue against the use of the polar body as a diagnostic material for mtDNA disorders, unless the purpose is for the selection of embryos that are completely mutation free," concludes Dr. Steffann. "Indeed, all mutation-free polar bodies were found to be associated with mutation-free eggs. Unfortunately, because the number of mutation-free eggs is low in women who have mtDNA mutations, the PCD option would dramatically decrease the successful pregnancy rate."

Source: Eurekalert
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
What's New on Medindia
World Disability Day 2022 - The Role of Innovative Transformation
Diet and Oral Health: The Sugary Connection May Become Sour
World AIDS Day 2022 - Equalize!
View all
Recommended Reading
News Archive
Date
Category
News Category

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Health Insurance - India 

Most Popular on Medindia

Blood - Sugar Chart Diaphragmatic Hernia Daily Calorie Requirements Hearing Loss Calculator Turmeric Powder - Health Benefits, Uses & Side Effects Sinopril (2mg) (Lacidipine) Nutam (400mg) (Piracetam) Pregnancy Confirmation Calculator Indian Medical Journals Accident and Trauma Care
open close
CONSULT ONLINE WITH A DOCTOR

×

Preconception Diagnosis Procedure May Pose Health Risks Personalised Printable Document (PDF)

Please complete this form and we'll send you a personalised information that is requested

You may use this for your own reference or forward it to your friends.

Please use the information prudently. If you are not a medical doctor please remember to consult your healthcare provider as this information is not a substitute for professional advice.

Name *

Email Address *

Country *

Areas of Interests