Genetic testing, as defined by the National Institutes of Health, is a type of medical test to identify changes in chromosomes, genes or proteins. Results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder.
Being a carrier of a genetic disease means that even though neither parent exhibits symptoms, one or the other can pass a disease to a child. If both partners are carriers of the same disease gene, each of their children has a 25 percent chance of being born with the disease itself. Eighty percent of babies with genetic diseases are born to parents with no known family history of that disease, making early genetic screening critical to planning for a healthy family.
Jewish genetic testing has come a long way since 1969, when doctors discovered the enzyme to do genetic testing to determine whether parents were carriers of Tay-Sachs Disease. Mass screenings for the disease began in 1971, and today there are virtually no cases of it among Jews. The incidence of Tay-Sachs has declined by more than 90 percent because of scientific advances and volunteer community activism that made screening for the disease a routine occurrence in synagogues, Jewish community centers and, eventually, routine medical care.
Thanks to advances in medicine and technology, many other Jewish genetic diseases have been identified. They include Cystic Fibrosis, Spinal Muscular Atrophy, Gaucher Disease, Tay-Sachs Disease, Usher Syndrome Type 1, Glycogen Storage Disease Type 1a, Familial Dysautonomia, Canavan Disease, Lipoamide Dehydrogenase Deficiency, Nemaline Myopathy, Bloom Syndrome, Walker-Warburg Syndrome, Maple Syrup Urine Disease, Fanconi Anemia, Niemann Pick Disease, Mucolipodosis IV, ABCC8 Hyperinsulinism, Usher Syndrome Type 3 and Joubert Syndrome.
While each of these diseases is rare, collectively the risk is meaningful. One in four Jews is a carrier for a Jewish genetic disease, and now screenings can be done in a panel to help people to prepare for a healthy family. The keys are to educate people and make the testing accessible to the greatest number of people. Although Tay-Sachs has been nearly wiped out in the Jewish community, the struggle to end preventable genetic disease is far from over. Many of the other preventable genetic diseases are even more prevalent in the Jewish population than Tay-Sachs was. What can be done about them?
JScreen, a national nonprofit public health initiative aimed at preventing Jewish genetic diseases, was launched as a pilot project in Atlanta in 2010, screening for the 19 genetic diseases most prevalent in Jews. The organization has tested thousands of people from all over the country since its national launch in 2013. Based at Emory University, Jscreen has become a nationwide project that provides affordable, accessible and comprehensive genetic screening, including remote services. The organization now screens for more than 200 diseases. To be at risk for most of these diseases, both parents must carry the same recessive gene.
Although Tay Sachs carrier screening necessitated blood enzyme testing, current sequencing methodology enables highly accurate testing to be performed on saliva. When, in infrequent cases, blood enzyme testing needs to be added to saliva testing, a JScreen genetic counselor notifies the parties involved and helps them to arrange to have the test performed.
When people register for a genetic screen kit at jscreen.org, the organization mails a test kit to their home. Test subjects spit into a tube and mail the saliva sample to the Jscreen lab. A genetic counselor follows up by reporting the results either by phone or secure video conference and providing genetic counseling as needed. If people have health insurance, the cost is $149; if not, it is $349.
According to Karen Arnovitz Grinzaid, an assistant professor of human genetics at Emory University and JScreen’s executive director, “While the focus is on the Jewish community, screening is encouraged for anyone planning to have a family. So many people don’t hear about genetic screening until they show up pregnant in their doctor’s office. At that point, if they are a high-risk couple, they don’t have as many options to help them plan ahead for a healthy baby. Genetic screening is something people should ideally do before they get pregnant. Awareness is the key.”
ILENE SCHNEIDER IS A CONTRIBUTING WRITER TO JLIFE MAGAZINE.