Nested IF functions in Median causes error in array

I have looked at a few solutions in this forum and tried their answers, but not been able to reach a solution. I have a data set I want to determine a conditional median for.

Sample Dataset:

Desired Outcome: I want to find the median of Ages, if the BD column has an entry of FSGS or MCD.

My current formula is:

{=MEDIAN(IF(BD="MCD",IF(BD="FSGS",Age)))}

But I keep getting a #Num! error.

I have checked that the "age" field are formatted as numbers. The BD field are formatted as General (but I have gone through and retyped each to ensure there were no leading spaces etc)

I can't seem to work out the problem, can anyone can help??