GRRM probably read Shakespeare, Victor Hugo, Vonnegut and many other authors and without doubt is familiar with the archetypal character of a grotesque male, usually with small statue but with big impact on the plot.
We have no lack of those in world lit. There is the evil genius iii. Richard, the noble and pure Gwynplaine, who lost his commoner love Dea - she was chased away when the hero's aristocratic lineage was revealed, there is also Emperor Claudius as described by Graves, a brilliant strategist shunned by his family for being a cripple,
Miles Vorkosigan, whom Tyrion reminds me of most (and it's apperently not just me) and there are loads of smartass and angsty characters both in history and lit, who were ridiculed by their milieu because they were cripples / had a medical condition like dwarfism.
GRRM himself didn't share with us what gave him the inspiration for Tyrion, but it's unlikely he was modelled after a single character. Tyrion has elements of the grotesque, the deprved dwarf and many other tropes... and after all, the author is influenced by his culture, environment and so on. Likely that the author couldn't pinpoint what influenced him even if he wanted to tell us.