The task is to identify the odd pair from the given alternatives based on a pattern in letter sequences. We'll examine each option:

1. OMQ:
   Convert each letter to its positional number in the alphabet: O(15), M(13), Q(17). The pattern is +2, +4 from the first letter.

2. TPR:
   Convert each letter to its positional number in the alphabet: T(20), P(16), R(18). The pattern is -4, +2 from the first letter.

3. TRV:
   Convert each letter to its positional number in the alphabet: T(20), R(18), V(22). The pattern is -2, +4 from the first letter.

4. VTX:
   Convert each letter to its positional number in the alphabet: V(22), T(20), X(24). The pattern is -2, +4 from the first letter.

Observing the patterns:

• OMQ: +2, +4

• TRV: -2, +4

• VTX: -2, +4

• TPR: deviates with -4, +2

Therefore, the odd one out is TPR as it does not follow the +2, +4 or -2, +4 pattern of the other options.