DF508 is a Delta F508. It's the most common CF gene in the world (yes, the world). It's a Class II mutation. ( <a target=_blank class=ftalternatingbarlinklarge href="http://www.cysticfibrosismedicine.com/CFdocs/CFText/gene.htm">Class info</a> )
I don't know about the other one (especially with the unusual specifics behind it), but you can read some about it <a target=_blank class=ftalternatingbarlinklarge href="http://www.genet.sickkids.on.ca/cftr/MutationDetailPage.external?sp=89">here</a> .