In my last article on the topic of MECP2 duplication syndrome, I discussed the first step in understanding what it is and how it happens. In this article, I will discuss what types of symptoms you can expect to see in a person who has been diagnosed with MECP2 duplication syndrome. It is important to note that the rare girls diagnosed with this disease tend to show less severe symptoms than boys due to the phenomenon of x inactivation. However, if the duplication translocates to another chromosome, girls can have symptoms just as severe as boys.
The first symptom parents in particular may notice is hypotonia, a low muscle tone often referred to as “floppy baby syndrome.” When my Anna was a baby, she would often flop backwards when she was being held if she wasn’t fully supported. I’m sure there were other examples of her weakness, but we really didn’t know enough to notice. We just thought she was a bit skinny and slow to develop, which is probably the next thing you notice. Development may be mildly to severely delayed. We kept taking Anna for well-child checkups and she wasn’t hitting the milestones she was supposed to hit. (Is she waving bye-bye, saying ma-ma, sitting down, turning around? No). She would seem to do these things very late, but she got to where she would do them. For example, Anna did not crawl until she was ten months old, while many babies begin to crawl at six months. We just thought she was a little behind but she would catch up.
Poor speech development will also occur. We feel really hurt because Anna is completely verbal in communication. She still says things we can’t understand even now at seven years old, but we start with pictures, pointing and teaching basic sign language to communicate. A very special story for me is when I first found out that Anna said, “Mommy.” She was saying “Ah-di”, but we couldn’t discern that from any of the other babble she was continuously making. One day I asked her to say mommy and she said ah-di and I thought, “Is she saying mommy?” Then I had to leave the house and when I came back she ran up to me saying, “Ah-di, Ah-di!” It was a priceless moment that I could never forget. My baby was calling me mommy. She calls me “nonny” now, and I’m told she probably always will. I’ll give her the benefit of the doubt, though: I think she’ll call me mom! Unfortunately, many children with MECP2 develop very few words into adulthood. I’ve been told that even the best performing men have fewer than 10 words.
Mental retardation is another serious feature of MECP2 duplication syndrome. In Anna’s case, she is seven years old and she underwent surgery at approximately three. Until now, this has been the envy of many other MECP2 moms because more often we hear of even more severe delays, like nine years operating at nine months. As a result, many MECP2 children do not learn to walk. Seizures are often reported with MECP2. Typically, tonic-clonic seizures are the most commonly seen. These are epilepsy-type seizures. There may also be atonic seizures in which the child’s head falls forward and he or she is spaced out for a moment. In Anna’s case, she had the absence seizures known as staring episodes. She seems to have “developed” these as we haven’t noticed them in a long time.
A particularly dangerous effect of MECP2 is the case of recurrent infections. The reason it can be serious is that diseases like pneumonia can recur over and over again and it has been recorded as one of the reasons why 75% of men with the disease get it before the age of 25. In Anna we see a predisposition to the disease, but never respiratory problems that can so often occur with this disease. However, it keeps her out of school for a long time, as she seems to have every bug within a hundred mile radius.
You may also see autistic behavior. We tested Anna for autism and were told that she has the behaviors, but not enough for her to be diagnosed. Her geneticist said just because she hasn’t been officially diagnosed doesn’t mean she doesn’t have it, it could be a very mild form.
Finally, you may notice gastrointestinal problems. I know we do. Constipation is a constant problem in our home and we must take precautionary measures such as giving clear laxatives in their drinks. Sometimes we forget, and there have been times when we have had to administer an enema. Eating high-fiber foods might help, but because of hypotonia, it’s very difficult to get Anna to eat well. She wants foods that are easy to chew and swallow, like soft pudding or crackers or crunchy pretzels.
These are the main signs and symptoms you will see if your child or someone you know has MECP2 duplication syndrome. The investigation is still ongoing, and there could be a lot more information to come. If you would like to support research, please make a donation to Baylor College of Medicine in Houston, TX and specify your intention that the funds go towards MECP2 research.
