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What is Pierre Robin Sequence?


Note: The treatments listed on this website may vary to the treatments you have available in your country. This website is set up in such a way that we try to accommodate and help all those affected with PRS Worldwide.


PIERRE ROBIN SEQUENCE / SYNDROME (PRS)

Pierre Robin (pronounced “Roban”) Sequence or Syndrome (PRS) is a condition present at birth, in which the infant has a smaller-than-normal lower jaw (micrognathia) or set back from the upper jaw (retrognathia), a tongue that falls back in the throat and obstructs the airway (glossoptosis), and difficulty breathing. Most infants, but not all, will also have incomplete closure of the roof of the mouth (cleft palate), and is commonly U-shaped.


Pierre Robin was a French physician who first reported the combination of small lower jaw, cleft palate, and tongue displacement in 1923.

Pierre Robin Sequence, also known as Pierre Robin Malformation, is a congenital condition of facial abnormalities in humans. PRS is a sequence: a chain of certain developmental malformations, one entailing the next. PRS affects males and females equally. It can occur in all ethnic groups and has been identified in countries throughout the world.


HOW COMMON IS THIS CONDITION?

PRS is rather uncommon, classified as a rare disease. A German prospective study reported an incidence of 12.4 per 100,000 live births (read more). In contrast, cleft lip and/or palate occurs once in every 700 live births.


WHAT CAUSES THIS CONDITION?

The basic cause appears to be the failure of the lower jaw to develop normally before birth. At about 7-10 weeks into a pregnancy, the lower jaw grows rapidly, allowing the tongue to descend from between the two halves of the palate. If, for some reason, the lower jaw does not grow properly, the tongue can prevent the palate from closing, resulting in a cleft palate. The small or displaced lower jaw also causes the tongue to be positioned at the back of the mouth, possibly causing breathing difficulty at birth. This “sequencing” of events is the reason why the condition has been classified as a deformation sequence. For some patients, these physical characteristics may result from another syndrome or chromosomal condition. The most common is Stickler Syndrome.


SYMPTOMS

  • Cleft soft palate
  • High-arched palate
  • Jaw that is very small with small (receding) chin
  • Jaw that is far back in the throat
  • Repeated ear infections
  • Small opening in the roof of the mouth
  • Tongue that is large compared to the jaw


WHAT PROBLEMS CAN BE EXPECTED WITH THIS CONDITION?

PRS, like most birth defects, varies in severity from child to child. Some children may have more problems than others. Problems in breathing and feeding in early infancy are the most common. Parents need to know how to position the infant in order to minimize problems. Infants with this condition should NOT be put on their back, to prevent the tongue from falling back into the airway, for example needing to stay in a lateral (on the side) or prone (on the tummy) position which helps bring the tongue forward and opens up the airway.


In moderate cases, the patient will need to have a tube placed through the nose and into the airways to avoid airway blockage. In severe cases, surgery is needed to prevent a blockage in the upper airway. Some patients need surgery to make a hole in the windpipe (tracheostomy).

Feeding must be done very carefully to avoid choking and breathing liquids into the airways. The child may need to be fed through a tube sometimes to prevent choking. Babies with a cleft palate will need a special cleft feeding device (such as the Haberman Feeder). This is related to the difficulty in forming a vacuum in the oral cavity related to the cleft palate. Infants who are unable to take in enough calories by mouth to ensure growth may need supplementation with a nasogastric tube. Given the breathing difficulties that some babies with PRS face, they may require more calories to grow (as working of breathing is somewhat like exercising for an infant)


The paediatrician or ear, nose, and throat specialist will also carefully monitor the baby for ear disease. Virtually all children with cleft palate are prone to build-up of fluid behind the eardrum. The placement of ventilation tubes in the eardrums may be recommended to reduce fluid build-up. Since ear infections can cause temporary hearing loss that can affect speech and language development, the infant’s hearing should also be monitored from early infancy by an audiologist.


Infants, when moderately to severely affected, may occasionally need nasopharyngeal cannulation, or placement of a nasopharyngeal tube to bypass the airway obstruction at the base of the tongue. In some places, children are discharged home with a nasopharyngeal tube for a period of time, and parents are taught how to maintain the tube. Sometimes endotracheal intubation or tracheostomy may be indicated to overcome upper respiratory obstruction.


In some centers, a tongue lip adhesion is performed to bring the tongue forward, effectively opening up the airway. Mandibular distraction (Jaw Distraction) can be effective by moving the jaw forward to overcome the upper airway obstruction caused by the posterior positioning of the tongue. Given that a proportion of children with PRS will have Stickler syndrome, it is important that a child with PRS have an evaluation by an ophthalmologist in the first year of life looking for myopia that can be seen in Stickler syndrome. Because retinal detachment that can occur in Stickler syndrome is a leading cause of blindness in children, it is very important to recognize and be thoughtful of this diagnosis.


WILL FUTURE CHILDREN BE AFFECTED?

It is important to understand that PRS can occur by itself (described as “isolated”) or as a feature of another syndrome. Parents who have had one child with isolated Pierre Robin Sequence probably have between a 1 and 5% chance of having another child with this condition. There have not yet been enough large-scale studies to make more accurate predictions.


When PRS is observed in patients with Stickler Syndrome, Velocardiofacial Syndrome, or Treacher Collins Syndrome, genetic/chromosomal factors will influence whether more affected children will be born. PRS also occurs in children with environmentally-induced (“teratogenic”) syndromes such as Fetal Alcohol Syndrome and Fetal Hydantoin Syndrome. It is extremely important that an infant born with PRS be evaluated by a geneticist, who will thoroughly investigate the possibility of an associated syndrome.


HOW IS THE CONDITION TREATED?

The goals of treatment in infants with PRS focus upon breathing and feeding, and optimizing growth and nutrition despite the predisposition for breathing difficulties.


Gastroesophageal reflux (GER) seems to be more prevalent in children with PRS. Because reflux of acidic contents in the posterior pharynx and upper airway can intensify the symptoms of Robin sequence, specifically by worsening airway obstruction, it is important to maximize treatment for GER in children with PRS and reflux symptoms. Treatment may include upright positioning on a wedge (a tucker sling may be needed if the baby is in the prone position), small and frequent feedings (to minimize vomiting), and/or pharmacotherapy (such as proton pump inhibitors).


  • Cleft Palate

The cleft palate, if present, needs to be surgically closed. The timing of the surgery depends on the child’s individual growth and development, but it is generally repaired between the ages of 6½ months and 2 years by a plastic or maxillofacial surgeon. Because children with cleft palate are at higher risk for delayed or defective speech development, they should be monitored by a speech pathologist throughout early childhood.

In many centre’s there is now a cleft lip and palate team comprising both of these specialties, as well as a coordinator, a speech and language therapist, an orthodontist, sometimes a psychologist or other mental health specialist, an audiologist, an otorhinolaryngologist (ENT surgeon) and nursing staff. The glossoptosis and micrognathism generally do not require surgery, as they improve to some extent unaided, though the mandibular arch remains significantly smaller than average. In some cases jaw distraction is needed to aid in breathing and feeding. Lip-tongue attachment is performed in some centre’s, though its efficacy has been recently questioned.


  • Jaw Distraction

In many patients, the lower jaw (mandible) grows rapidly during the first year of life. In some children, the jaw may grow so quickly that by the time the child is approximately four to six years of age, the profile looks normal. Children who do not experience this “catch-up” growth may require surgery on their jaws. It is not fully understood why children’s jaws grow at varying rates.


Distraction osteogenesis (DO), also called a “Mandibular Distraction”, can be used to correct abnormal smallness of one or both jaws seen in patients with Robin Sequence. Enlargement of the lower jaw brings the tongue forward, preventing it from obstructing the upper airway. The process of DO begins with preoperative assessment. Doctors use three dimensional imaging to identify the parts of the patient’s facial skeleton that need repositioning and determine the magnitude and direction of distraction. They may then select the most appropriate distraction device or sometimes have custom devises fabricated. When possible, intraoral devices are used.


DO surgery starts with an osteotomy (surgical division or sectioning of bone) followed by the distraction device being placed under the skin and across the osteotomy. A few days later, the two ends of the bone are very gradually pulled apart through continual adjustments that are made to the device by the parents at home. The adjustments are made by turning a small screw that protrudes through the skin, usually at a rate of 1 mm per day. This gradual distraction leads to formation of new bone between the two ends. After the process is complete, the osteotomy is allowed to heal over a period of six to eight weeks. A small second surgery is then performed to remove the device.


WHERE CAN CHILDREN BEST BE TREATED?

Since children with PRS may have a variety of health concerns, parents are strongly advised to locate a craniofacial center where evaluation and treatment planning can be coordinated by an experienced multidisciplinary staff composed of health care professionals from many different specialities.


POSSIBLE COMPLICATIONS

  • Breathing difficulties, especially when the child sleeps
  • Choking episodes
  • Congestive heart failure
  • Death
  • Feeding difficulties
  • Low blood oxygen and brain damage (due to difficulty breathing)
  • Pulmonary hypertension

WHEN TO CONTACT A MEDICAL PROFESSIONAL

This condition is often seen at birth.

Call your health care provider if your child has choking episodes or breathing problems. A blockage of the airways may cause a high-pitched crowing noise when the child breathes in. It can also lead to blueness of the skin (cyanosis).

Also call if your child has other breathing problems.


PREVENTION

There is no known prevention. Treatment may reduce the episodes of breathing problems and choking.


PROGNOSIS

Children affected with PRS usually reach full development and size. However, it has been found internationally that the child is often slightly below average size, raising concerns of incomplete development due to chronic hypoxia related to upper airway obstruction as well as lack of nutrition due to early feeding difficulties or the development of an oral aversion. However, the general prognosis is quite good once the initial breathing and feeding difficulties are overcome in infancy. Most PRS babies grow to lead a healthy and normal adult life.