Ammonia poisoning when young can cause this, or even a long trip in a bag.
But I have a feeling seeing the photo, that its a genetic defect, and one that can't be cured.
In any spawn, there will always be a number of genetic defects, and the breeder should be culling fish that have them. But....some are very subtle when young, and often go un-noticed until a fish is 3-4" or older. This is one reason why, dropping off 100 (give or take) 1" cichlid fry at a LFS can be problematic, it would not be out of line to say that 20 out of every 100 could have some sort of defect, anything from a curved spine, to curved gills, to a short body, which in my opinion should all be culled before distribution. And when dealing with hybrids such a FHs, the % may be higher because of the mixing of genes.