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

Pierre Robin Sequence Contracting 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 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.