Based on the appearance of these two siblings, which pharyngeal arch appears to be most affected?
Pharyngeal arch 1
Pharyngeal arch 2
Pharyngeal arch 3
Pharyngeal arch 4
Here both siblings show mandibular hypoplasia. Mandible develops from 1st pharyngeal arch Pierre Robin sequence and Treacher Collins syndrome are both associated with mandibular hypoplasia.
miscellaneous