Answer:
There can be things common if a human and cat have extra sex chromosomes (XXY) that includes they are both males and they both have Klinefelter syndrome
In both human and cat, sex chromosome is represented as XY and because of an extra sex chromosomes (XXY) both will be male as female has XX sex chromosome.
Both human and cat will suffer from Klinefelter syndrome because extra chromosome can cause any hormonal or genital disorder and Klinefelter syndrome is a disorder in which humans have small undescended testes or small penis.