Friday, May 16, 2008

Count the Ribs

You are doing a newborn exam and find a baby with narrow, sloping, "weird" shoulders. The baby seems unusually flexible; you can bring his shoulders almost together in the midline in front. You identify the abnormality on the CXR above. You remember that this diagnosis often involves delayed closing of the fontanelles (which may remain open to adulthood), defective bone formation, short stature, supernumerary teeth, and abnormal tooth eruption.

Challenge: The defective gene is a transcription factor called what?

Hint: The number of ribs you count isn't important, but you may notice something interesting while counting the ribs.

Image shown under fair use.

1 comment:

Craig said...

Count the Ribs

The CXR shows hypoplasia or aplasia of the clavicles, suggesting the diagnosis cleidocranial dysplasia. This is an autosomal dominant condition due to a mutation in CBFA1 which is a RUNX transcription factor. There are many different manifestations, only a few of which are included in this case.

Sources: UpToDate;;