1 2 aim

#apaperaday: Cognitive and behavioral functioning in two neurogenetic disorders: Duchenne muscular dystrophy and Neurofibromatosis type 1

In today’s #apaperaday, Prof. Aartsma-Rus reads and comments on the paper titled: Cognitive and behavioral functioning in two neurogenetic disorders; how different are these aspects in Duchenne muscular dystrophy and Neurofibromatosis type 1?

Today’s selection is from PLOS ONE by Hellebrekers et al. The study compares cognitive and behavioral function of Duchenne and Neurofibromatosis 1 patients. Doi 10.1371/journal.pone.0275803

Duchenne is a muscle wasting disorder caused by dystrophin loss, neurofibromatosis is characterized by tumor formation (neurofibromas) due to decreased production of neurofibromin, a tumor suppressor protein. Both proteins are also expressed in brain & involved in neurodevelopment. 

Both DMD and NF1 patients also have increased risk for cognitive and behavioral problems. Here authors compared 38 age matched DMD and NF1 patients age 6-16. As DMD only occurs in boys, only male NF1 patients were included. 37/38 DMD patients were using steroids.

Autism spectrum disorder and attention deficit hyperactivity disorder were found in both cohorts as were learning difficulties at comparable frequencies between DMD and NF1 and higher frequency than unaffected children. IQ was comparable too.

However DMD patients tended to have lower IQs. Behavioral reports from parents showed comparable incidences for both groups as well. Aggression was more common in DMD but this can be due to steroid treatment. Interestingly the comorbidities are very similar between the diseases.

Authors discuss that dystrophin and neurofibromin are both involved in GABAergic receptors where dystrophin loss lead to increased excitation while neurofibromin loss leads to increased inhibition. Even though opposite effects occur the results are similar clinical apparently.

Authors discuss the limitations of there retrospective study – the usual problems of missing data. Also the sample size was relatively small. Authors stress that comparing comorbidities between male and female NF1 patients should be done in the future.

Finally authors stress that comorbidities need to be treated. The fact that a symptom is part of a disease does not mean you should not treat it if treatment is available- which for eg ADHD and learning difficulties are available.