Disease from microbe, a nameless disorder (6,7)
I believe the answer is:
german measles
'disease' is the definition.
(German measles is an example)
'microbe a nameless disorder' is the wordplay.
'microbe' becomes 'germ' ('germ' can be a synonym of 'microbe').
'disorder' indicates anagramming the letters (I've seen 'diseased' mean this (I've seen this in other clues)).
'nameless' is an anagram of 'nmeasles'.
'germ'+'a'+'nmeasles'='GERMAN MEASLES'
'from' is the link.
(Other definitions for german measles that I've seen before include "Rubella" , "complaint" , "viral illness" .)