Pierre Robin sequence is a set of abnormalities in a baby that develops during pregnancy. It is called a sequence because one of its features − an undeveloped lower jaw − starts off a sequence of other malformations while a baby is developing in utero.

When a baby has a lower jaw that is unusually small, the child’s tongue forms further back than normal. When this happens, the tongue can block the baby’s airway causing breathing problems. It can also affect how the roof of the mouth forms, often leading to cleft palate.

Pierre Robin sequence is named for the French dental surgeon who first identified and researched this sequence of conditions. (Robin is pronounced Ro-BAHN.) It is also referred to as PRS, Pierre Robin, Robin sequence, Pierre Robin syndrome, and neonatal tongue-based airway obstruction.

Pierre Robin affects an estimated one in 8,500 to 14,000 people.