DWQA QuestionsCategory: QuestionsCPT2 deficiency – identified gene mutations
Sheryl Mulder asked 4 years ago
Dr. Vockley, could you share a bit more about what is known & not-known with the relationship between type of mutation and severity or classification of type of cpt2 deficiency? My kids were told their newborn does not have the “common” mutation (I assume Ser113Leu) and I have read the 60% of the primarily muscle weakness/pain types of the disorder has this genetic mutation. They were really only told that the mutation their son has is not as known and that the only way they will be able to determine is when he has his first “episode” and goes to the ED and gets assessed by testing, etc at that time. They also were given the reassurance that since he is doing well and they are following all instructions, that is the very best for him continuing to do well… They were also told that it would surprise their specialists if he would develop cardiomyopathy… in other words… can’t be sure .. but likely would fall into the more muscular form… It sounds like a lot of the information is based on the fact that this is a rather newly recognized condition and newborn screening has not been around long, so they don’t have as much information on the various mutations and forms…. Anything you can add? I appreciate your information. I know you cannot give false reassurances.

1 Answers
INFORM Physician answered 4 years ago
Ms. Mulder, It’s an inexact science. Clinical course in other patients is always the most useful indicator of severity. After that, enzyme activity is useful. We know the common mutation (the Ser113Leu) has significant residual activity, thus accounting for it’s mild nature. Almost all other mutations that have been tested fall in between this one and zero. My usual approach is to measure enzyme activity in skin cells. It’s an easy test and it gives useful information. Another test called acylcarnitine profiling can also be helpful to predict severity. They would be good starts. Hope this helps. Dr. Vockley