Genetics

Something that came as a surprise to me (although it’s relatively old news): Geneticists claim to have identified the locus of genes that correlate with primary enuresis.

I knew that surveys (dating back to the 1970s) suggest that a child is very likely to wet the bed (about 75% probability) if both parents did. If one parent wet the bed, chances are about even that the child will. If neither parent wet the bed, a child generally will not; a child with no bedwetting in the family tree (parents, grandparents, uncles and aunts) is rarely a bedwetter. Those probabilities are for primary enuresis, that is, for a child over the age of 6 who has never been dry. Secondary enuresis (such as mine), which starts after being dry for some time, is not genetically correlated.

The interesting thing — to me, at any rate — is that geneticists have identified the locus of several genes that appear to be correlated between parents who were bedwetters and their children who wet the bed. Some genes appear to be dominant, some to be recessive.

Some of the genes appear to be sex-linked. That would explain why, as children get older, boys are more likely to still wet the bed than girls are. That’s reversed in my family: My sisters wet the bed to a much later age — 16 or 17 — than my brothers did, and my son was dry while his older sister was still wetting most nights.

A few caveats:

My degrees are in mathematical disciplines. I have a low regard for the rigor of medical studies based on surveys. I doubt that the surveys allow the reported precision of the correlations. I doubt that the samples are large enough or representative enough for the correlations to be very convincing. Still, if one allows a wide margin of error, even at an anecdotal level there is a basis for belief.

While I have a background in statistical methods, I’m no geneticist. My knowledge of biology is limited to 9th-grade public-school frog-chopping (for which I got the worst grade of my academic career) and (like most people with math degrees) I regarded biology as only slightly more respectable than alchemy. On the other hand, geneticists do appear to take science seriously and a pointer to an actual gene is interesting.

Advertisements

4 thoughts on “Genetics

  1. Pingback: Reassure | Bedwetting Mom

  2. I have to agree that genetics play a part in bedwetting. I also have done considerable reading on the subject and agree with what’s been said here that it is generally more boys than girls that wet the bed and that if both parents were bedwetters the kids have a larger chance of bedwetting than if just one parent was a wetter.

    One study I read quite awhile ago said that if a family had bedwetters of both sexes that the girls would probably wet longer than the boys. No real reason for the thought was given.

    In our house all the kids still wet the bed and nightly. Protection is worn and this too shall pass.

  3. I am the mother of four girls, ages 7, 9, 11 and 14. All four are bedwetters. Bedwetting has been a problem in both my family and my husbands as well. I myself was a bedwetter until I was 16. My two sisters wet the bed well into their teens as well. My husband wet the bed until he was 12 and his oldest sister was in high school before she was completely dry. We have decided that it would be best if they all wore protection until they are dry. The girls so far have not complained.

  4. It is worthy to note that there are several genes hypothesized to cause bedwetting for example, most cases of bedwetting are autosomal dominant, which mean you only need to inherit the gene from one parent to display the phenotype or physical characteristics. For example, having free earlobes is an autosomal dominant trait which means you only need to inherit the gene from one parent to have free earlobes. However since you said you have secondary enuresis, it is unlikely your children have autosomal dominant inheritance for the bedwetting phenotype unless your husband was a bedwetter since that specific gene is only related to primary enuresis. There are other explanations for why your children have primary enuresis if neither parent did. It could be a recessive gene which means that the trait will only manifest if both copies of that specific gene are inherited. And example of that is the genetic disorder cystic fibrosis. Healthy parents can have a sick child when they don’t have any symptoms that is because they are carriers of the disease but only have one copy of the trait so the dominant gene cancels out the recessive. This may be the case for your children since you said the majority of your siblings and both parents had a history which makes the perfect genetic mixing ground for the bedwetting phenotype if possibly both parents were carriers. It could also be a case of incomplete dominance which mean that although they may have one copy of the dominant and one copy of the recessive, both genes display their traits. This is seen in wavy hair. Curly hair is dominant and straight is recessive. You would expect a person who inherited one gene for curly hair and one for straight to have curly hair since curly hair is dominant right? Wrong, due to incomplete dominance, both traits manifest giving wavy hair. This may be true for your children’s bedwettig since you mentioned they aren’t wet every night, so this looks like both the wet and dry phenotype are showing but the dominant trait is not completely dominant hence they aren’t nightly wetters but often enough for it to be a problem. The last cause is mutation. When most people hear mutation they think of the three eyed fish from the Simpsons. But in reality, mutations of that type are very rare and virtually everyone has thousands of mutations but they are so insubstantial they are asymptomatic. For example, blue eyes are a mutation, yet people never picture blue eyed people when they hear the word mutation. The cause of my bedwetting is most likely mutation, I have three x chromosomes(the average female has 2) and I have autism. I have absolutely no family history of bedwetting. But I think of this as a blessing rather than a curse. Autism has allowed me to excel in science and I am writing a scientific paper soon to be published at age 19. I can cite my sources if you would like.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s