Muscular Dystrophy - does anyone have any further knowlegde?

[scaredpuppy]

Hi,

Hopefully someone can shed more light. My husband and I have been together for 10 years, we had our first child (healthy and happy) when I was 30 and he was 35. I am now 35 and he is 40, we are trying for second (I wanted a gap).

For some reason my anxieties are through the roof and I think its because my BIL had health issues with his children. My husband has 4 brothers and 1 sisters. All have had 'healthy' children bar one of his brothers.

This brother actually had an arranged marriage to a cousin (please no judgement, that are in their 50s now so was a while ago). The cousin is on his mums side if that helps.

They had one healthy daughter, a second daughter that was later diagnosed with health issues, she lost all mobility and speech and I think it was a form of DMD, she passed away at age 20. They had another daughter that passed away at the age of 2 before the second was diagnosed and they also had a termination. After some genetic testing they decided to go for a 4th, another daughter that seems healthy, now 7 years old, maybe some behavioral issues but other than that she's fine.

Rest of the 15 nieces and nephews from the remaining brothers and sister are all fine.

For some reason I have convinced myself that because of our ages anything that my husband could be a carrier for will affect our unborn child. Am I being rational or is this just anxieties getting to me?

Does anyone know more about DMD and can tell me more on how it is passed down?

So I'm not a doctor but know maybe a little bit ! Are you sure it was DMD? DMD is on the X chromosome so is quite rare in girls and it is generally mild.

As DMD is on the X chromosome, if your husband had it he would most likely be affected and you would know. It's generally women who are carriers as they have two X chromosomes and so can have one "faulty" gene but it's compensated for by the normal gene.

This is just for DMD, there are other types of muscular dystrophy.

I'm no medical professional but I would think the issues their children faced was because the parents were cousins. Especially if no one else had issues and have married outside of the family.

I'm not 100% sure if it was DMD, my sisterinlaws English isn't that great so I don't think she'll know exactly what the condition was. The family just put it all down to the couple being cousins but I know usually defects happens when both the mother and father have similar defects in their DNA which is more likely with family members.

She wasn't mobile, in a wheel chair, had to be fed by her carers, couldn't speak. She was fine until she was 3. Her sister that passed away as a baby I'm not sure what happened but she was taken to hospital and didn't make it.

I've read for this to happen there would need to be something in the DNA that they both share..but again this is just from reading on Google.

DMD is carried on the X chromosome, its recessive so is only expressed in boys because they only have one X chromosome. For it to occur in girls both X chromosomes would need to carry the fault but then the father would most probably have DMD. There are other types of MD though which may have different inheritance pattern.
Other common genetic diseases seen in consanguineous marriages ( first cousin) include Thalassemias which have similar level of disability which develops during childhood and significantly shortens life expectancy. Symptoms start to appear around 2-3 yrs of age.

The good news is that where these conditions have occurred in families it is possible for screening to see if you or your DH carry any genetic diseases particularly if you have a history of close family marriages.
The South Asian community have an increased risk and there are NHS clinics in Birmingham and Bradford where you can be screened if you have concerns.
We have a gene fault in our family, not much is known about it and although it can shorten life it doesn’t impact until 50s/60s. It is very rare and little research is available because it doesn’t impact everyday life until mid/old age.
Screening will put your mind at rest, it does seem as though the faulty gene has come from your BIL’s wife’s family though.

Thank you very insightful.

My BILs wife has a brother and sister and their children are also fine.

Would that not mean both BIL and SIL both have the same faulty gene? Perhaps to much of an assumption for me to make...

With gene mutations carried on the X chromosome you have a 50/50 chance of inheriting it. So brother and sister may not be carriers. The same for your BIL and the rest of the family. They can all be carriers but don’t necessarily pass on the gene to their children.
If you are worried then have a chat with your GP. They may refer you to a genetic clinic to see if you or your DH carry any genes. It’s very much a lottery whether you carry a gene or not. Recessive genes particularly those not on the x or Y chromosome can remain hidden until someone marries another carrier and then the gene has the opportunity to express itself. This is more likely in families that intermarry generation after generation.