Blank Overlay Used To Show Alert Messages Automatically

You are about to leave bloomssyndromeassociation.com.

Click Cancel to return or OK to continue.

News Spotlight   |   Print Page   |   Contact Us   |   Sign In   |   Register
MORE ABOUT GENETIC TESTING: 23andMe
Share |

23andMe, a personal genomics and biotechnology company billed as the largest DNA ancestry service in the world, plans to add the Ashkenazi Jewish mutation to its panel of genetic tests. What is the "Me" value of this new test?

In current healthcare practice, genetic tests for recessive disorders, with a few notable exceptions, depend on first having a child who has a diagnosed clinical entity. For example, most couples don't know they carry a mutation in one of their BLM genes until they have a child with Bloom's syndrome. Having had a child with Bloom’s syndrome, and having obtained a correct diagnosis, it is highly likely that each parent carries a disease-causing BLM mutation on one of the two homologous chromosomes 15; that is, each parent is a mutation carrier. With this information, each parent can obtain further information about the mutation they carry by sequencing the BLM gene in each parent’s DNA. Then, this information can be used prenatally, and others in the family can also find out if they are carriers, which can be useful information in certain circumstances.

The notable exception relates to populations with founder mutations. Most Ashkenazi Jews with Bloom's syndrome are homozygous for a unique and distinct, disease-causing BLM mutation. Because it is possible to devise a simple genetic test to identify this distinct mutation, an Ashkenazi Jewish person can get a genetic test to identify this mutation in the DNA and to learn before marrying or having children whether or not he or she carries the mutation. Indeed, many Ashkenazi Jewish couples get tested for a panel of mutations that are relatively common in the Ashkenazi Jewish population. In this setting, a couple can find out their carrier status ahead of time. If each person carries a disease-causing mutation in the same gene, for example in BLM, then each pregnancy has a one in four chance of being homozygous for the mutation. Persons homozygous for the BLM mutation have Bloom’s syndrome.

The Ashkenazi Jewish gene test panel is available from a variety of medical labs. The approach to genetic testing by Ashkenazi Jews is a proactive model for genetic testing, and it contrasts with the reactive model that everyone else has to follow. But technological advances in DNA sequencing are making the proactive model of genetic testing available to everyone. Scientists predict that couples will get their genome sequenced to learn about the risks of diseases for their prospective children, and in particular the risks of recessive genetic disorders like Bloom’s syndrome. Knowing carrier status ahead of time gives couples options, ranging from selective marriage, to pre-implantation genetic testing coupled with in vitro fertilization, to selective termination.

23andMe is not a unique leader in this field, but the inclusion of the Ashkenazi Jewish BLM mutation in their gene test panel increases the value to Ashkenazi Jews. 23andMe may add many more such genes to their panel in the future. That said, the technology that 23andMe is currently using is not the technology of the future—it is not DNA sequencing. DNA sequencing is applicable to all populations and all situations. With specific gene tests, such as the Ashkenazi Jewish test for BLM mutation, the information is population-specific. Understudied populations are often left out of these gene test panels. Moreover, most mutations that cause genetic disease are so rare they are never going to be included in a specific gene test panel.

Lastly, in the early stages of the company's development, 23andMe overstepped the boundaries, moving too early to inform customers of disease risks based on incomplete information. In addition, this company, like many other genetics service companies, likes to deal directly with the consumer. This practice is problematic because genetic information is not going to be understood by everyone getting it. The standard of practice in medical genetics clinics is to get genetic counseling before and then after genetic testing. This practice was put into place to make sure that patients understand the information they were going to get and then understand the interpretation of the results once they got it. Although this practice is labor intensive, it is necessary for patients so that they can make informed decisions.

The imperative for this practice is based on a history of cases in which genetic testing was subject to abuses or misunderstandings. An important example was government-mandated sickle cell disease carrier testing in African Americans in the early 1970s. Most of the recipients of the testing were school children. They did not have the opportunity to give informed consent and they didn’t understand the impact of the genetic testing information transmitted: there was a perception that race motivated the testing and a stigma arose around carriers of the hemoglobin S mutation. There can be unintended negative consequences to genetic testing, and to avoid them we need to be careful and vigilant about the setting and purpose for genetic testing.

BSA Blog

2016 Bianco Family's Fundraiser

Second annual fundraiser in memory of Vanessa Bianco and for the benefit of all individuals and families affected by Bloom’s syndrome. All proceeds from the 2016 campaign will go to Bloom’s Syndrome Association in support of its mission.

For more information and to make a donation, please visit the CrowdRise webpage for the 2016 Bianco Family's Fundraiser.

2017 Bianco Family's Fundraiser

Third annual fundraiser in memory of Vanessa Bianco and for the benefit of all individuals and families affected by Bloom’s syndrome. All proceeds from the 2017 campaign will go to Bloom’s Syndrome Association in support of its mission.

For more information and to make a donation, please visit the CrowdRise webpage for the 2017 Bianco Family's Fundraiser.

About the BSA | Contact the BSA | Privacy Policy | Terms of Service | Disclaimers

Copyright Bloom's Syndrome Association, Inc.