August 20, 2009

Microcephaly. It's Official.

At today's neurology appointment Bertrand's head measured (and remeasured) in the 2nd percentile while his height and weight are still in the 50th percentile. His head hasn't shrunken. It just hasn't grown in several months. This means he has microcephaly--a small head. Below is a very helpful explanation of microcephaly from an email exchange with Bertrand's genetic counselor, Rena.

"In medical terms, we use 'microcephaly' to describe a head that is below the 3rd percentile. However, "relative microcephaly" would mean smaller relative to the other measures. Because B's height and weight are around 50th %, we would say he has relative microcephaly. Usually, though, in conditions such as chromosomal breakage conditions, we are looking for true microcephaly. [...]

And, especially in the case of "relative microcephaly" we always look at the family trends. [...] What is often most important, though, is a child's trend over time. For instance, are all measures normal at birth and then does ONLY the head size become smaller? (This, of course, doesn't mean that the head is actually shrinking, just that it isn't growing along with the rest of the body). This is termed 'acquired microcephaly' which can be a type of 'relative microcephaly'. In fact, acquired microcephaly is what we generally see in individuals with a MeCP2 mutation. [...]

This would mean he has relative microcephaly, and, if the OFC dips below 3rd %, acquired microcephaly."

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