What is Creatine Transporter Deficiency?

I've started telling people about my son's diagnosis. Until recently I would say that he has some delays and that we see various therapists to help him progress. I was paranoid that they'd google it and find out about the intellectual disability part which is something I am not dealing well with and can't talk about. I'm also tired of pretending he doesn't have a diagnosis and I want to raise some awareness of this rarely diagnosed metabolic disease. Some people might stumble upon this blog looking for information so here it is:

Creatine Transporter Deficiency affects primarily the brain and the muscles of affected children. The creatine transporter is important to move creatine from the blood into the tissues and when it is not working, the body is unable to get it into the cells where it is used for energy production. Clinical features include seizures and variable developmental concerns ranging from mild intellectual disability (sorry, no can do on the MR term that is rampant in research papers and all over the internets but I digress) to more severe forms. Unfortunately doctors are unable to predict where children may fall within this spectrum so us parents get to sit around and obsess over this, especially late at night when exhausted and in desperate need of sleep.

Creatine Transporter Deficiency is a genetic condition caused by a change in a gene (so, a mutation) on the X chromosome. The gene in question is called the SLC6A8 gene and males (XY) are more affected because they have one X chromosome whereas females (XX) have two X chromosomes. It was explained to me that males have no working copy of the gene to compensate for the mutation.

The specific gene mutation was identified in my son's SLCA8 gene and it is a causative mutation given the fact that it stops the protein from being made. Tests confirmed that I am not carrier for the disease therefore this was either a brand new change that occurred shortly after conception (much like winning the lottery, only not) or there is a small chance that I might carry the mutation only in a small proportion of my egg cells. Super!

A really good overview of creatine deficiency syndromes can be found here.

In other random news, our primary computer died during a power outage and our spare clunker is on its way out so...new computer!