Yes - the symptom being milk draining from the nostrils.
It usually affects the soft palate, and sometimes the hard palate. Cleft lip does occur, but is rare. Pneumonia is common in affected foals, and they tend not to thrive. (Very mild cases, however, are sometimes not detected for weeks or months).
The cure is surgical repair, which is a major surgery that tends to take forever to heal. It's harder to treat in horses than in humans and dogs because a horse's mouth doesn't open very wide. The prognosis is guarded even in the best cases, and even those that survive tend not to be fit for showing and competing.