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

From Wikibooks, open books for an open world
< Handbook of Genetic Counseling
Jump to: navigation, search

Pierre Robin Sequence

Contracting[edit]

  • How have things been going since your last visit to genetics?
  • What questions or concerns would you like to discuss today?
  • Set agenda for session

Etiology[edit]

  • 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 COL1A1 (1p21) or COL1A2 (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 hydantion 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[edit]

  • 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[edit]

  • 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[edit]

  • 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[edit]

  • 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[edit]

  • 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[edit]

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

References[edit]

  • "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[edit]

The information in this outline was last updated in 2000.