Squibs have genes to do magic?

[Jen Reese]

No: HPFGUIDX 146363

Thinking about Mrs. Figg or Filch doing spontaneous magic later in 
life made me wonder if that's possible. I thought the whole point of a 
Squib is that he/she doesn't have magical genes; Even immersing 
themselves in the magical world as Filch does, how could they suddenly 
perform magic? Magic is supposedly due to a dominant gene, so it seems 
like it would be equivalent to changing your eye-color, but then I 
have a mental block about genetics.

The problem is I honestly can't think of anyone else who could qualify 
for magic later in life and surprise Harry other than either Filch or 
Figg (since the Dursleys are out). Both have made such a big deal 
about not being able to perform magic. I think the fact Filch has 
actually tried to use a wand if he did the Kwikspell course probably 
tips the scales in his favor. He wouldn't be a Squib though, but 
latently magical and just lived his life thinking he was a Squib.

Jen, knowing she's splitting hairs <g>.