Ventral Scale mutation

[Kohm]

Hello,

My friend's green gave birth to 23 young, out of which most had a common mutation where the ventral scales were split, forming "paired" ventral sclaes. In some cases, only some of the scales were split. In others, the entire length of scales were split.

Is this mutation common? What are possible causes? Can it be prevented from happening again?

Thanks
[addsig]

[python04slayer]

Are the ventral scales located on the underside of the snake?, b/c if they are my ball python has that goin' on towards the end of his tail ending a bit before his vent.