Pierre-Robin Sequence is not a syndrome, it’s a sequence. While it is a collection of features, one happens because of the one that came before.

The features are:

• Retrognathia/micrognathia (posterior mandible or very small mandible)
• Glossoptosis (downwards/posterior displacement of the tongue due to the small mandible
• Airway obstruction (because the tongue is in the way)

Pierre-Robin Sequence is associated with cleft palate (50% of children with the sequence have cleft palate). There are two proposed theories:

1. The first is that the tongue simply gets in the way of the palate from fusing
2. The second is that the tongue prevents the newly fused palate from staying fused (this is currently the more popular theory)

PRS, though not a syndrome itself, is associated with multiple syndromes including Stickler Syndrome, velocardiofacial syndrome, fetal alcohol syndrome and Treacher Collins Syndrome.