Discussion 3 - Developmental disorders

This discussion deals with developmental disorders and genetic illnesses during an individual's development. The objective of this discussion is to get insights on the importance of genes and environment for the development of a human being. The discussion is three hours long. During the discussion the scenario is discussed together with a facilitator. Please bring a laptop or two to every group. It is also a good idea to quickly go through the various links on this page before the discussion.

The discussion centers around the development of the body during embryogenesis. Sometimes this process is not functioning, resulting in developmental disorders. The causes of certain developmental disorders are still unknown, but medical research into the causes is shedding light on the cellular and molecular mechanisms. For certain diseases, the genetic variations causing the developmental disorders are well defined and well known.

You can visit Teeter's home pages at www.apert.org.

Scenario

A couple comes to the clinic where you work. Their daughter was born with deformed hands and mild problems with the closure of the sutures in the skull. The developmental disorder in the hands is called syndactylia (webbing of digits). The child has now been diagnosed as having Apert's syndrom, based on mutations in the FGFR2-gene that code for a receptor for the fibroplast growth factor (FGF), that have been identified with gene analysis. More information on the syndrome can be found in the home pages of the Swedish Apert society, including an information folder on Apert's. More information can be found OMIM, at the Swedish Socialstyrelsen pages and on Teeter's home page. Remember that you can even search for information at PubMed or in a review article.

The parents have a few questions that they would like to discuss with you

• What is the cause of Apert's syndrome?
• How common is it?
• What is wrong with the gene?
• What exactly is meant by a "receptor gene"?
• If only one single gene is affected, why is it that the body is affected in so many different ways? (E g head and hands). Draw a schematic illustration when you explain this.
• The parents would like to know how early it is possible to tell if an embryo has Apert's syndrome.
• Is the syndrome related toDown's syndrome?
• Is Apert's syndrome a result of aneuplody?
• Give examples of different types of common aneuploidies.
• Are there other syndroms related to Apert's syndrome?
• Why is that not all parts of the body seem affected?
• Where did this change in a gene (a mutation) come from?
• Has the child inherited the mutation from the parents?
• Why is it that their child specifically has this syndrome?
• Could they have done anything (before or during pregnancy) to prevent the child from getting the syndrome?
• Would intake of extra folic acid have helped?
• The parents are approximately 40 years old. Does the risk for Apert's syndrome correlate with the age of the parents?
• During the pregnancy, the mother had the influenza and viral gastroenteritis. Would this have have any connection to the Apert's syndrome?
• If they couple has more children, is there a risk that even the other children will have Apert's?
• How does gene diagnostics work (or is it possible?) How early can you diagnose Apert's?
• The parents have read in the newspaper about "gene therapy". Can you explain the concept for them? Could their child be cured or helped with gene therapy, by replacing the gene with the mutation?
• Finally, the parents would like to find more about the syndrome. They have a relatively high level of education. Which sources of information would you recommend for the parents. Motivate your recommendations.

Reflect on these questions and discuss through them together with your group and the facilitator. The parents probably could have even more questions. Can you think of a few? Discuss these with the group.