chr22q11

[Aclamity]

I've gotten bits and pieces of this disease from UW and FA, so I wanted to see if I'm putting it together properly. Sounds like chr22q11 is important in neural crest migration, which affects development of the midface, thymus, parathyroids, and aorticopulmonary septum. So deletion of chr22q11 can lead to abnormalities in any or all of the above.

So when someone gets persistent TA or Tet of Fallot is this usually due to chr22q11, or are there multiple things that can cause those defects? Same question for DiGeorge: is it always a chr22q11 deletion or are there other things that lead to 3rd/4th branchial pouch problems?

Just trying to wrap my mind around it and see if they are all part of the same syndrome. thanks

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[mdeast]

I've gotten bits and pieces of this disease from UW and FA, so I wanted to see if I'm putting it together properly. Sounds like chr22q11 is important in neural crest migration, which affects development of the midface, thymus, parathyroids, and aorticopulmonary septum. So deletion of chr22q11 can lead to abnormalities in any or all of the above.

So when someone gets persistent TA or Tet of Fallot is this usually due to chr22q11, or are there multiple things that can cause those defects? Same question for DiGeorge: is it always a chr22q11 deletion or are there other things that lead to 3rd/4th branchial pouch problems?

Just trying to wrap my mind around it and see if they are all part of the same syndrome. thanks

Just briefly looking at this.

(1) Right. 22q11 abnormalities are a set of diseases. DiGeorge is one of the typical presentations, but patients can have any combination of these symptoms depending on the exact 22q11 event that occurred.

(2) I think other developmental abnormalities can affect these process. In other words, TOF/PTA patients do not necessarily have DiGeorge syndrome or any 22q11 abnormalities. Wiki says TOF it can be of both genetic and environmental influences and is also associated with mutations in other genes (VEGF, JAG1, etc.). About 50% of PTA's are associated with DiGeorge/22q11 abnormalities, but other genetic disorders, teratogens, etc. can also contribute.

(3) I think by definition DiGeorge syndrome is 22q11. At least, you would never see it show up on boards by any other definition.