Its not that they dont have ligand binding domain, its that there is a mutation that makes it less sensitive to that ligand. The same ligand is not activating it like before.
So this guy probably doesnt understand very well the test made to him, fin isnt mutagenic according to what we know. The professor must have used tgat reverse transcription pcr to simulate the result of his epigenétics.
So there is some degree of silencing of the gene.
Androgeb receotirs form heterodimers ewith GC and Progesterone receptirs right?
Btw, my comment about this being linked to teratogenecity is obviously wrong Bécause in that case the drug would be actively inhibuting 5ar ofc.