Heterozygous state

Question

Dear ladies and gentlemen,
I 34 (female) as well as my daughter 7 suffer from CF.
My question,
in my son (14), CF has been exculded 2 times but why is it written in a doctor's letter (gastroenterologist)
"We would recommend additionally a renewed genetic counselling to exclude a compound-heterozygous CF. At the moment there is a heterozygous state, however in the last time some new mutations became known."

This heterozygous mutation has been diagnosed in my son (14) in the year 2003.
My CF itself has been diagnosed per instance at a human genetic expert when I was 29 years old.
Is there a special hospital for human genetics except Gießen and Hannover, that conduct ongoing blood test?
Yours sincerely and many thanks,

Answer

Hello,
This question can not be answered without detailed knowledge of the molecular genetic results of the family. If the 14 year old son is heterozygous (and therefore does not suffer from CF) or if he is comound-heterozygous (and therefore after all possibly suffers from CF) can probably be answered already with the results of the molecular genetic investigation of the questioner, her husband, as well as the 2 children. For this I recommend a genetic conselling on the basis of these results. From the clinical point of view the questions arise, how the CF has been excluded 2 times, and why the 14 year-old son has been at an appointment at the gastroenterologist. The proposal of the gastroenterologists, of a renewed human genetics counselling, is probably the consequence of a clinically unclear situation.
Sites for human genetic counselling are found in any bigger city. A list of such sites can be found on the Hompage of the Germany Society for Human genetics (www.gfhev.de).
Molecular investigations for CF are conducted by more than 50 laboratories in Germany, whereby not all laboratories conduct the complete investigation (sequencing and search for deletions/insertions). The extent of a probably necessary ongoing investigation should be clarified in advance with the testing laboratory via the site of the genetic counselling.
Yours sincerely,
Prof. Stuhrmann-Spangenberg

25.06.2009