A panel of experts is considering adding tests for diseases that develop in adulthood to the standard genetic tests given to young couples when they are starting a family. Currently, these tests only cover diseases that develop in childhood.

The panel is leaning toward recommending that tests for adult-onset diseases be added, but that the couple be required to receive genetic counseling first and have the option of refusing the tests.

“It’s important that the couples get a detailed explanation of the tests and their implications, and they have the option of refusing,” one senior geneticist explained.

The National Bioethics Council, which advises the Health Ministry, set up the panel in response to a proposal to add one specific test, for a mutation of the GNE gene that is common among Jews of Persian origin and causes HIBM, a neuromuscular disease for which there is currently no treatment. HIBM begins with muscle weakness, usually when the patient is in his thirties, and ends in total paralysis.

At a recent discussion by the panel, proponents argued that allowing such testing could eventually stop transmission of the disease to a new generation. But opponents argued that it would expose people to knowledge they might not want: in this case, the fact that they would almost certainly be totally paralyzed later in life.

“Many people refuse testing, saying they don’t want to know if they’re going to die young,” the senior geneticist said.

Opponents also fear the expanded testing would lead to a rise in abortions. An Israeli study published in the journal JAMA in 2007 found that even with a treatable disease like Gaucher’s, 25 percent of couples found to be carriers of the disease aborted.

“The tests included in the [genetic] survey today are for diseases that start in childhood,” noted Prof. Ephrat Levy-Lahad, who co-chairs the National Bioethics Council. “The question that must be asked is whether it’s justified to abort a pregnancy because of a disease that will develop only in adulthood.”

The council is also considering expanding the genetic counseling that accompanies the standard genetic tests, with a decision on that matter expected in about six weeks.

Because the current tests relate only to diseases that develop in childhood, this counseling only addresses the possible implications for the couple’s children, while ignoring the implications for the parents. Yet a genetic mutation can affect the parent even if he hasn’t developed the disease it causes. For instance, a mutation of the FMR-1 gene can cause autism or developmental delays in children, but women who carry this mutation face an increased risk of early menopause and of developing neurological diseases such as Parkinson’s later in life.

Genetic testing is very common in Israel, with about 50,000 couples a year undergoing it, according to the Health Ministry. Not all the tests in the standard package are covered by the national health insurance plan, but supplementary insurance offers discounts on the rest.