How Pierre Robin Sequence occurs, or why, is still unclear, but thought to be the result of poor development of the jaw at about the 6th to the 11th week of foetal life. This poor development affects the series of "normal" formation patterns in the face and neck and these changes lead to a 'sequence' of events where the result is structural deformity of varying degree or severity.
For reasons still yet unclear, the head of the foetus does not rise off the chest causing the forward growth of the jaw to be restricted . The tongue then remains back in the mouth cavity and becomes forced up into the roof of the mouth (palate). This prevents the palate from closing as it normally would. It also explains why the mouth cavity is smaller than normal, the tongue may be difficult to see, airway structures may be narrow and mouth muscles are at risk of being misplaced, malformed or uncoordinated.
As yet there is no evidence that isolated Pierre Robin Sequence is related to anything specific - be it medication, x-rays or diet. Why the disorder occurs is still being investigated. It is very difficult to view on a scan (ultrasound) and there are no tests to diagnose this condition before birth. As far as medical science has been able to determine to date, there is nothing you could have done to prevent this from happening and nothing you did to cause it either.
Pierre Robin Sequence can also appear as part of a genetic or chromosomal
disorder. There is a number of these conditions and one of the more common of these is Sticklers Syndrome (for more information see Dave Hawley or Sticklers Involved People or Sticklers in Australia), which affects the eyes, hearing, palate, heart and joints. Others include Treacher-Collins Syndrome, Velocardiofacial Syndrome (try information and support) and Foetal Alcohol Syndrome to name just a few.
For this reason, your child will be very carefully assessed to see if any other disorder is involved. Blood tests and other types of examinations may diagnose some of these. Your child's doctors will explain these tests and their results. If a genetic or chromosomal condition is suspected or found, you will be given advice and genetic
counseling to help you understand whether there will be risks to future pregnancies. You will also be advised about the long-term significance for your affected child. Always ask your doctors for a more simplified or detailed explanation if you are unsure about these tests or their results.
Some children may not be diagnosed with genetic disorders even though such an irregularity exists. Diagnosis may be made for some as they grow towards school age, or their teens. For others, diagnosis may not come until adulthood. Some cases of Pierre Robin Sequence are the result of rare chromosomal anomalies which are still being discovered and identified. If this situation is suspected, some genetic tests may be repeated at intervals throughout a child's life as medical science learns more, and 'gene mapping' (the science and study of chromosomes, their components and structure) becomes more precise. If at any stage you are concerned, always seek out your medical team for advice. The Directory of Genetic Support Groups may also be a helpful resource.
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Copyright © 1999. Last Updated - 24/02/99 23:39:04