CHARGE syndrome: CHD7 mutations, heart defects and overlapping syndromes
|PhD ceremony:||dr. N. Corsten-Janssen|
|When:||October 11, 2017|
|Supervisors:||prof. dr. C.M.A. (Conny M.A.) van Ravenswaaij-Arts, prof. dr. R.M.W. Hofstra, prof. dr. L. Kapusta|
|Where:||Academy building RUG|
|Faculty:||Medical Sciences / UMCG|
CHARGE syndrome is a rare combination of multiple congenital malformations of the eyes, ears, cranial nerves, heart and other parts. Features vary from person to person, also in the rare occasions when multiple family members are affected. The major cause of CHARGE syndrome is a change in the CHD7-gene, which leads to less or the wrong CHD7 protein being made.
In this thesis we present the changes we have found in the CHD7-gene and we have created an online CHD7 database (www. CHD7.org), which currently contains information on 750 different changes. We also wrote a guideline to help clinicians determine if CHD7 analysis is warranted in a patient.
We then studied the effect of CHD7 changes in the heart. Our results showed some types of heart defect are overrepresented in people with CHARGE syndrome, but these changes are not a major cause of non-syndromic heart defects.
Lastly, we studied syndromes that look like CHARGE syndrome and tried to determine why this overlap occurs. We showed this clinical overlap often points to an overlap at the molecular level.
Sometimes it is not clear if a change in the CHD7 gene is disease-causing. Future research should therefore focus on a method to check the function of the CHD7 protein to help with interpreting DNA analysis. Furthermore, evidence-based guidelines for medical follow up of CHARGE patients need to be developed.