This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
A 19-year-old woman presents with primary amenorrhea. Her physical examination is normal, and she has female sex characteristics and breast development. The only abnormality is the absence of body hair. Genetic testing reveals an XY chromosome pattern. Which of the following mechanisms is most likely to explain her phenotypic pattern and amenorrhea? 
Select and explain. 
A. estrogen receptor defect, B. excess hormone production, C. androgen receptor defect, D. decreased hormone production
C: androgen receptor defect
Answer: C: androgen receptor defect 
Explanation: Disease states, due to abnormal intracellular receptors, include androgen insensitivity; cortisol resistance; vitamin D-dependent rickets, type II; thyroid hormone resistance; and pseudo hypoaldosteronism. Androgen insensitivity syndrome is caused by a mutation in the androgen receptor, and it affects 1 in 100,000 chromosomal males. Because the androgen receptor is X-linked, it only affects males. The phenotypic presentation can vary from complete androgen insensitivity (female external features) to partial insensitivity causing ambiguous or normal male features and infertility. There are several different types of cell membrane receptors.