The karyotype of a patient with androgen insensitivity Syndrome is
**Core Concept**
Androgen insensitivity syndrome (AIS) is a genetic disorder caused by mutations in the androgen receptor gene, leading to resistance to androgens (male sex hormones) in individuals with XY chromosomes. This results in a spectrum of phenotypes ranging from partially to completely resistant to male development.
**Why the Correct Answer is Right**
In individuals with AIS, the presence of a Y chromosome is evident through karyotyping, but the androgen receptor is defective, preventing the conversion of testosterone to dihydrotestosterone (DHT). DHT is crucial for the development of male external genitalia, and its absence leads to the characteristic features of AIS. The karyotype will show a 46,XY pattern, indicating the presence of a Y chromosome, but the clinical presentation will be female or ambiguous.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not accurately represent the karyotype associated with androgen insensitivity syndrome. The karyotype of individuals with AIS is typically 46,XY.
* **Option B:** This option is incorrect because it suggests a different chromosomal abnormality not associated with androgen insensitivity syndrome.
* **Option C:** This option is incorrect because it implies a chromosomal sex that does not align with the typical presentation of androgen insensitivity syndrome.
**Clinical Pearl / High-Yield Fact**
A key feature of androgen insensitivity syndrome is the presence of a normal 46,XY karyotype despite a female or ambiguous phenotype. This highlights the importance of considering both genetic and phenotypic characteristics in diagnosing sex development disorders.
**Correct Answer: A. 46,XY.**