Don’t Blame Mother

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It shouldn’t be about blame, of course, in the first place. But, what is incomplete about the diagram below?

When a child is diagnosed with an X-linked recessive disorder, the inheritance pattern is often illustrated with a diagram like this one. Notice where the buck stops.

What parents might be shown

What could going back one more previous generation reveal? There are (at least) five possibilities.

First, let’s be clear, the mother might not be a carrier to begin with.

There might not have been a genetic alteration previous to the diagnosed child; the mutation (to use the “m-word”) just sprang up suddenly in the early embryotic divisions of the affected fetus, causing the disorder. In that case, the mother is not a carrier. However, this diagram might be used to explain how things usually work, even when the mother has not been  identified as a carrier through genetic testing.

A second possibility: the mother does have the mutation, but only in some of her ova, or egg cells. She, also, would not be identified as a carrier because the mutation does not affect the DNA in her entire body. A blood test would not reveal the mosaicism (that means some egg cells are affected, others are not) because the DNA in the rest of her body, and many of her ova, does not code for the disorder.

Further possibilities occur when the mother is identified by genetic testing as a carrier in the usual sense (each pregnancy having 25% chance of an affected son, 25% chance of a carrier daughter, 50% chance of an unaffected child, as illustrated in the diagram). But how does she happen to be a carrier?

That brings us to the third possibility: A “spontaneous mutation” occurred making the mother a carrier without previous genetic history in the family. It is often estimated that in some X-linked recessive disorders, around 30% of affected pregnancies result from such “out of the blue” genetic changes.

©Voronin76/Shutterstock

Fourth possibility: She was a carrier daughter of a carrier mother. The damaged gene “runs in the family,” although there may never have been an affected son born to anyone before this. Of course, everything said above about the mother, can also be applied in the grandmother’s case.

Fifth possibility: Because a daughter gets an X chromosome from each parent, the mother could have inherited the mutation from her father! Gosh, that’s something you seldom hear!

©Lisa F. Young/Shutterstock

But yes, in spermatogenesis, mutations occur. If the sperm carrying an X chromosome with an altered gene fertilizes the egg, well, there you have it, a new carrier daughter. No one will suspect, there will be no reason to test, until an affected grandchild of the new carrier’s father is born and begins to manifest symptoms of a disorder that no one knew ran in the family…because it didn’t.

I’m not sure why knowledge of these different scenarios should affect the burden of guilt felt by many mothers who are implicated in genetic inheritance patterns, but I strongly suspect that it does. After all, guilt is an emotion and therefore irrational to begin with. It is easy to say, “It’s nobody’s fault.” But in the case of X-linked recessive disorders, given the way the inheritance has been diagrammed for generations, is it any wonder so many moms feel it all came from them?

Is it stigmatizing to be identified as a carrier of a genetic disorder?

When a disorder “runs in the family,” it might be a source of stigma. Whether it is or not, all depends.

© onder turan

Being stigmatized, or marked as different and undesirable, involves the loss of social standing. One is marked as being less than others and is aware of being so marked.

© Ioannis Pantzi

Usually, there are negative stereotypes associated with stigmatized groups. The classic  work on the subject is Stigma: Notes on the Management of Spoiled Identity (1963), by  Erving Goffman, in which stigma is described as tainting and discrediting. Stigma is  defined by a social environment because it results from the way others see us. To the  degree that we “buy into” their judgments, shame is also attached to conditions that are  stigmatized.

The opposite of stigma can be the healthy pride that comes from feeling respected by others. Whether others respect us can depend upon how well we are fulfilling our social roles as defined by our surrounding culture. Health and beauty are generally respected and admired. In reproductive matters, producing offspring, especially males, is a source of pride of accomplishment for men and women in many societies. For any particular culture, the more social standing that results from producing children, the more likely it will be that having no children, or imperfect children, will result in social stigma.

© cofkocof

We can regulate stigmatization by controlling our immediate social environment. The people we associate with, the viewpoints we read or listen to, and the information we divulge can all affect the number of negative evaluations coming at us.

For more information on stigma & health:  http://www.stigmaconference.nih.gov/papers.html

© 2011  Jane Belland Karwoski

One Way Of Looking At It

Some of the people I have spoken with have a sibling with a genetic disorder. They have expressed how much they value their sib and the experiences they have had with or because of their brother or sister. There is often strong loyalty to that person, disability and all. They don’t want to say or feel anything that would imply that the world or their family would have been better off without them. They therefore have conflicted feelings about preventing the birth of another affected child, even though they would have loved to be able to eliminate the health problems of their sib.

You have to admit that it could hit you pretty hard if “everyone” wants to avoid having another someone-like-you come into the world! On the other hand, many affected with a disorder say they hope their relatives are not also born with the problem.

This is related to a hot topic in the disability community. A high-profile instance is when deaf parents want a deaf child, which, if their deafness is genetically based, they could arrange through IVF (in vitro fertilization) and PGD (pre-implantation genetic diagnosis) and selecting an affected embryo for implantation.

So I think a good topic to start with is what Marque-Luisa Miringoff called The Social Cost of Genetic Welfare. Her 1991 book was probably the first I read that dealt with the social controversy surrounding, shall we say, human perfectibility? Miringoff is a sociology professor at Vassar and director of The Institute for Innovation in Social Policy. The gist of the book is to examine the changes in attitude toward the handicapped that are likely to follow the ability (of the privileged) to prevent disability. To take a common, though not technically inherited example, will we start looking even more askance at those with Down Syndrome, if we think that could have been prevented through prenatal testing and termination?

But as siblings realize, people only come in one model. That particular child could not exist apart from his or her disability—it’s a package deal. Yet, we don’t want to say a person is his or her disability. Just as none of us is his or her genome. There are many social, environmental factors at work—layers of paint upon the genetic canvas.

Any thoughts?