Pierre Robin sequence
A congenital sequence of facial malformations causing breathing and feeding difficulties.
Pierre Robin sequence (PRS) is a congenital condition involving facial abnormalities. Its defining features are a chain of events: an abnormally small lower jaw (micrognathia) leads to a displaced or retracted tongue (glossoptosis), which then obstructs the upper airway and causes breathing difficulties. A wide, U-shaped cleft palate often accompanies these features. PRS is classified as a sequence rather than a syndrome because it consists of a linked series of developmental malformations traceable to a single underlying cause.
- field
- Congenital defect
- known_for
- Facial abnormalities including micrognathia, glossoptosis, and upper airway obstruction
- associated_disorders
- Stickler syndrome, DiGeorge syndrome, fetal alcohol syndrome, Treacher Collins syndrome, Patau syndrome
Quick Facts
- Field
- Medical genetics
- Symptoms
- Micrognathia, glossoptosis, obstruction of the upper airway, sometimes cleft palate
- Onset
- During gestation, present at birth
- Causes
- intrauterine compression of fetal mandible, de-novo mutations (on chromosomes 2, 4, 11, or 17) or Stickler syndrome
- Diagnosis
- Physical examination
- Treatment
- Craniofacial surgery, oral and maxillofacial surgery
- Frequency
- 1 in 8,500 to 14,000 people
Facts from the source article.
Lore & Background
Pierre Robin sequence is characterized by an unusually small mandible, posterior displacement or retraction of the tongue, and upper airway obstruction. Cleft palate is present in the majority of patients. Hearing loss and speech difficulty are often associated with PRS. The physical craniofacial deformities may result from a mechanical problem in which intrauterine growth of certain facial structures is restricted, or mandibular positioning is altered. One theory suggests that early in the first trimester, some mechanical factor causes the neck to be abnormally flexed, compressing the chin against the sternoclavicular joint, interfering with mandible development. Alternatively, PRS may be caused by a genetic disorder, often due to a de-novo mutation at chromosome 17, with genes such as SOX9 or KCNJ2 implicated.
Reader's Guide
Pierre Robin sequence is significant as a congenital condition that presents immediate challenges to breathing and feeding in newborns. Management focuses on positioning the infant sidelying or prone to bring the tongue forward, with studies showing 63% of infants respond to prone positioning. Nasopharyngeal cannulation is favored as a less invasive treatment to maintain airway patency. Distraction osteogenesis may be employed to enlarge the lower jaw and advance the tongue. Cleft palate is generally repaired between 6½ months and 2 years. The condition often occurs as part of underlying disorders such as Stickler syndrome or DiGeorge syndrome, highlighting its importance in broader genetic and developmental contexts. Its legacy lies in understanding the mechanical and genetic bases of craniofacial development and improving neonatal care.
Did You Know?
- PRS is characterized by micrognathia, glossoptosis, and upper airway obstruction, with a wide U-shaped cleft palate commonly present.
- One theory for PRS is that early in the first trimester, neck flexion compresses the chin against the sternoclavicular joint, interfering with mandible development.
- Mutations at chromosome 17, including genes such as SOX9 and KCNJ2, have been implicated in PRS.
- Many infants with PRS respond to prone positioning for airway obstruction, though response rates vary across studies.
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