Sentence:  A team of international researchers has recently identified the first—ever genetic link to common <WSD>migraine</WSD> ("common <WSD>migraine</WSD>" refers to <WSD>migraine</WSD> without "aura", and it is the most common type of <WSD>migraine</WSD> that occurs). 
Meaning of the word marked with <WSD> tags:  A severe, disabling headache, usually affecting only one side of the head, and often accompanied by nausea, vomiting, photophobia and visual disturbances.