# Handbook of Genetic Counseling/Cleft Palate - Pierre Robin Sequence-2

Pierre Robin Sequence

## Contracting

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## Etiology

* Association of micrognathia, cleft palate, and glossoptosis
* Multiple anomalies caused secondarily by a structural anomaly
** Micrognathia or retrognathia at 9-11 weeks of embryonic development prevents tongue from descending from between palatal shelves
** Tongue prevents palatal shelves from growing together horizontally and fusing
** Causes tongue to be displaced, blocking airway
* About 80% of cases may be caused by a multiple anomaly syndrome
** 34% of Pierre Robin due to Stickler syndrome
** Due to mutations in COL2A1 gene usually at 12q13
** Also could be due to mutations in COL11A1 (1p21) or COL11A2 (6p21)
** Autosomal dominant disorder with 50% recurrence risk
** 11% of Pierre Robin due to VCF
** Deletion of 22q11
** Recurrence risk 50% if one parent has deletion
** Many other single gene disorders, some X-linked recessive disorders, recessive disorders
** Teratogenic exposure
** Fetal alcohol syndrome
** Fetal hydantoin syndrome
** Retinoic acid embryopathy
* Isolated Pierre Robin sequence
** May be due to fetal crowding due to presence of multiple fetuses, abnormal fetal position, uterine anomalies, or oligohydramnios
** Associated deformities may also occur
** Multifactorial inheritance
** Recurrence risk if one child with cleft palate 3-5%
** Recurrence risk if two children with cleft palate 10-12%
** Affected individual has 3-5% chance of having a child with cleft palate
* Incidence is about 1/2500 births for cleft palate

## Clinical Features and Natural History

* Craniofacial
** Often U-shaped cleft involving both hard and soft palate
** Small and symmetrically receded mandible
** May cause dental crowding
** Jaw may "catch up" in adolescence if due to mechanical constraint
** Flattened base of nose
* Growth and Feeding difficulties (long-term feeding problems 50%)
** Failure to thrive evident in neonatal period
** Poor suck due to cleft palate
** Inability to nurse, irritability, aspiration
** Often due to respiratory difficulties
* Respiratory complications
** Upper airway obstruction often present at birth or shortly after
** Deep pectus excavatum
** Cyanosis not common but may occur
** May be due to glossoptosis obstructing the epiglottis
** Complications of continuing airway disorder may include sudden death, failure to thrive, persistent deformation of sternum, decreased pulmonary function, cognitive effects of hypoxia
* Ears and Hearing
** Middle ear disease due to cleft palate
** Chronic ear infections may lead to conductive hearing loss
* Cognitive and motor development normal in isolated Pierre Robin sequence

## Testing Options

* Genetic testing may be offered if genetic syndrome is suspected
** Chromosome analysis
** FISH for deletion of 22q11
** DNA testing for mutations in collagen genes indicated in Stickler syndrome
* Level II ultrasound prenatally at 18-20 weeks gestation for cleft palate but difficult to identify

## Management and Treatment

* Overcoming feeding difficulties
** Important that baby learns to actively suckle
** Establish feeding routine that requires short feeding time
** Use special cleft palate nursing bottle
** Reflux may be treated with medication or regular breaks to burp
** May require NG tube or g-tube
* Cleft palate repaired surgically 9-18 months
** Weight, size of airway are factors in when surgery performed
** Must be sure lower jaw is wide enough to accommodate tongue once palate repaired
** Usually requires 1-3 day hospital stay
* Jaw distraction surgery now being performed on infants in some hospitals
* Tracheostomy may e required if severe airway issues
* Special services
** Speech therapy to prevent speech and language delays
** May require IEP from school or other services, particularly if caused by underlying genetic syndrome
* Chronic middle ear infections treated aggressively with antibiotics or PE tubes to avoid conductive hearing loss, speech and language delays

## Differential Diagnosis

* Most commonly associated with VCF or Stickler syndrome
* Some other associated syndromes include Myotonic Dystrophy, Campomelic dysplasia, Lenz syndrome, Nager syndrome, Treacher Collins syndrome, and Turner syndrome

## Psychosocial

* Frustration, impatience due to feeding difficulties in newborns
* Difficulty relating to baby due to physical appearance, inability to breastfeed
* Guilt, anxiety, depression, anger about diagnosis
* Assess support system

## Resources

* Pierre Robin Network
    http://www.pierrerobin.org/
* American Cleft Palate-Craniofacial Association
    http://www.cleft.com/
    800-242-5338

## References

* "Orofacial Clefting Syndromes: General Aspects." Syndromes of the Head and Neck (1990) 693-704.
* "Pierre Robin Fact Sheet." Pierre Robin Network. http://www.pierrerobin.org/
* Shprintzen RJ. "Robin Sequence." Management of Genetic Syndromes (2001) 323-336.

## Notes

The information in this outline was last updated in 2000.