> The more common form according to my wife

Not sure what relevance the source has here, but it’s not correct. Primary (AL) is the most common in the developed world and secondary (AA) elsewhere. There are some foci of ATTR but it is by far not the most common.

I should have mentioned my wife is a physician, apologies. The true prevalence of ATTR is not known since it's only been investigated for recently as described in the article. If you look up recent data you'll see a big difference.