The "Female" Side of Duchenne

It was a long time ago that I sat in the exam room and received the diagnosis. My boys had Duchenne. The diagnosis was followed by a series of questions about my family history, the doctor assuming that somewhere along the line, there was another boy long ago. In my case, there was no history. None. I asked every living member of my mother’s family what they knew, if there was someone who had an unnamed ‘problem’, someone who was weak, or a child who died young from an unnamed illness. One of my cousins talked about my "crazy Uncle Harry” who fell off the roof, but it hardly fit the picture I was looking for. I had a brother Jack, who died young, at the age of 42. A heart attack after jogging. He was my closest friend and I wondered if he might have had a mild form of Duchenne – decent muscle strength, but severe cardiomyopathy. It was always a question.

I guess it would have been easier to simply test my mother, but she had her own issues with the diagnosis. Catholic guilt. She had the sense that a god would punish her for past deeds and I did not want to create additional burden for her. I left it alone, an open wound. For years, I wondered. In retrospect, I wonder if I just wanted to be able to point the finger at someone else. I didn’t want to be the first carrier, the de novo mutation in my family. It seemed so unfair and it felt like I did something wrong somehow. OK, intellectually, I realize, spontaneous mutations occur frequently. The dystrophin gene is particularly susceptible based on its large size. Eric Hoffman suggests 1:10,000 egg and sperm cells carry the mutation as a new event. Random. Right, but emotionally it still hurts. Motherhood and guilt.

Just before the FACES meeting in Colorado, we met with Ivy Scherbarth and Angela Knight. It is always a question. Are you a carrier?. We discussed and compared carrier vs non carrier. Ivy had tears in her eyes as she had looked back through her family, tracing what must have been Duchenne generations back. Angela, not a carrier, said that either way, having a child diagnosed with a genetic disease is accompanied by guilt. I think she’s right. There is no way and no need to compare the feelings. Mom’s feel responsible. But there are more questions and strings attached to the word “Carrier” and the word stings somehow, sometimes feels like an indictment, with questions about prior knowledge, muscle weakness and concerns about the risk heart disease.

Carriers are working on two dystrophin genes, one carrying the mutation and one without. And we are hopeful that our cells opt to use the “good” gene, the gene that does not carry the mutation, producing normal quantities of dystrophin in every muscle and tissue of our bodies. But sometimes it does not work that way. When moms talk about this openly, some share stories of muscle cramps, weakness, fatigue. One mom recently mentioned she had a weak handshake and her doctor thought it was characteristic of a carrier. That sounds a little over the top to me as handshakes are personal, dictated by much more than muscle strength. I think the answer may be somewhere in the middle. Some moms have weakness ranging from mild to severe. These moms are referred to as ‘manifesting carriers’, their cells opting to utilize the genetic recipe for dystrophin that is inaccurate, incomplete. This is referred to as X-linked inactivation, where the cells essentially turn off the ‘good’ gene with the accurate recipe for dystrophin. And, depending on the degree of the X-linked inactivation, there will be weakness, from cramping to weakness to loss of function, sometimes severe.

Carrier moms also need to take care of their heart. Statistics suggest that 10% of female carriers are at risk. I’m not sure where that statistic comes from. I have seen some papers suggesting the risk is greater. To be honest, I think the statistic is not important as the fact that we need to take care of ourselves. As moms, we often ignore our health to take care of our family. How we feel is last on our list as long as we are getting out of bed and managing to get through the day. I think all women need to pay attention to their heart. Heart disease is common in women and it is essential that we keep our hearts beating strong for ourselves and for everyone who depends on us. Carrier or not – take care of your heart.

And girls with Duchenne. If a young man with Duchenne married a carrier of Duchenne, it is possible that they could have a daughter with Duchenne. I would guess this is indeed very rare. But it could happen. For the most part, girls with Duchenne have X-linked inactivation, where the cells turn off the normal or ‘good’ dystrophin gene. Depending on the degree of this X-linked inactivation, their progression could be the same as a boy with Duchenne. Because Duchenne affects boys 99% of the time, we talk about Duchenne in male terms. Every photo you see will show a boy. In the US, we are guessing around 10-15 girls have Duchenne. While Duchenne is not a club you want to join, I cannot imagine how it feels to be in the club but feel that you are standing in the back of the crowd, unnoticed.

I think this is a discussion we need to have – Carriers, manifesting carriers, girls with Duchenne. If you have any ideas about this, please let me know. You can always email me at Pat@parentprojectmd.org.

And to end my own personal story. I did have my mother tested just last year, assuming in my heart that she would be a carrier as well. She was not.

My father’s company manufactured Doctor bags, the old time doctor bags you may have seen in films. To this day, they are called “Schell bags”. Every Sunday, I would ride with him into town, to the factory (Schell Leather Goods) where he would light the glue pots, so that by Monday, when the men working in the factory arrived, the glue would have reached the appropriate temperature for the leather to adhere to the wood frame. I remember a strange sweet smell wafting through the plant after a few minutes. In conversations with other carriers, some mentioned that their fathers worked with chemicals – fertilizers, pesticides, stuff.

I’ll always wonder. It’s human nature.