"It is thought that Castar Semenya suffers from PAIS "
"It is thought that Duttee Chand suffers from CAIS "
Who said? We know:
"Dr Bermon, who has served as a member of the IAAF Medical and Anti-Doping Commission since 2006, has only seen one case where a female athlete was completely androgen insensitive. "
", Professor Ritzen stated that it is "easy" to determine complete insensitivity since the athlete will present no signs of virilisation at all. However, it is more difficult to determine partial androgen insensitivity. There is no specific test that can enable a precise quantification of the degree of partial insensitivity and exact grading is therefore "very difficult". Professor Hirschberg agreed that determining insensitivity involved a combination of physical evaluation and endocrine testing. He acknowledged the
process is "very complicated". "
In other words while some athletes do have CAIS, most cases of athletes with AIS are PAIS. AIS can be very strong P without being C.
As regards Caster Semenya, there are two reasonable explanations:
5ARD as per many cases in elite female athletes see e.g. www.ncbi.nlm.nih.gov/pubmed/23633205
or PAIS as again many cases
I would bet money on 5ARD, but I can't say for sure.
In terms of Dutee Chand, CAIS is actually quite unlikely in that PAIS can be quite strong without being C. There is not particularly any reason to assume Dutee Chand is completely androgen immune.