Frost Death Knights received some changes in the latest Patch 10.0.7 build on the PTR.
Frost Strike – Chill your weapons with icy power and quickly strike the enemy with both, dealing a total of [ 92% 91% of Attack Power ] Frost damage. Now costs 30 Runic Power (up from 25).
Breath of Sindragosa – Continuously deal [ 40.5% 50.6% of Attack Power + 40.5% 50.6% of Off-hand Attack Power ] Frost damage every 1 sec to enemies in a cone in front of you, until your Runic Power is exhausted. Deals reduced damage to secondary targets.