I would be interested to know how many subspecies of lions are currently considered to be genetically valid.  I've come across a PDF article on the Internet by lion experts saying that there seem to be 5 genetically distinct groups, or subspecies, of lions according to preliminary genetic research - (1) North Africa & India; (2) East Africa; (3) West Africa; (4) Southern Africa; (5) Central Africa.  Has this been confirmed by subsequent research?

For what I understand Lion subspecies taxonomy is still actively debated within the field. I've seen estimates between 2 (Africa and Eurasia) up to 6 or 8 depending on the source. And that just includes modern species, there are a great many fossil specimens that are argued as extinct subspecies of lion, including some in North America. Then there are those that argue that none of the subspecies are distinct enough and they should all be clumped together as a singular species.

You phrased your question as "genetically valid" which I think might lead to some confusion as using genetics is relatively recent and most past estimates (especially fossil taxa) were based on morphology not genetic sequencing.

Sorrry there's not straight answer for this one, biology can be tricky like that!

Just  to add - part of the confusion/disagreement stems from the fact that there is no agreed upon definition of what constitutes a valid subspecies. Although subspecies definition can have important political/conservation/management implications there is no defined biological criterion so people can (and do) frequently disagree.