IS BLANK not working

Hi: 

I have a dax statement and I have inserted ISBLANK statement in it. However, its not producing the result that I want. 

CurrentDAX =
IF(ISBLANK(CALCULATE
(DISTINCTCOUNT('TABLE1'[Column1]),
FILTER('TABLE1','TABLE1'[Column2]="ABC"),
)),0)

1) This statement is producing in Card =  (Blank)

2) When you remove the ISBLANK the card produces = 1

This is the correct answer. 

3) But sometimes there is no data and I want to put "If No Data then 0." So why isnt ISBLANK working.