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 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

 * 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