Illness that 'shut down' Tech3 MotoGP rookie Jonas Folger diagnosed

Folger has been out of action since what was initially presumed to be a case of mononucleosis ruled him out of the MotoGP race weekend at Motegi.

The 24-year-old German - who is contracted with Tech3 Yamaha through 2018 - has since missed rounds at Phillip Island and Sepang, and will not be present at this weekend's Valencia season finale either.

After visiting specialists in his native Germany, Folger has been diagnosed with Gilbert's syndrome - a genetic ailment that precludes the liver from correctly processing bilirubin.

Tech3 has revealed that Folger had been affected by the condition for a number of years and that it flared up ahead of the Motegi race, rendering him "bedridden".

"It's a huge relief that we now have a clear understanding of the situation and how to move forward,"said Folger.

"The past six weeks have been very difficult for me, not knowing what's happening or why my body shut down completely.

"I've been living with elements of this since 2011 but I've always been able to overcome it and we never really knew what it was.

"It's unfortunate that it took such a serious episode to finally diagnose the situation but I'm just thankful we now have some answers.

"I will be back and stronger than ever, fighting at the top of MotoGP."

A race winner in 125cc, Moto3 and Moto2, Folger currently sits 10th in the standings in his first MotoGP season.

His rookie campaign's highlight was challenging for victory on home turf at the Sachsenring before finishing runner-up to Marc Marquez.

Tech3's statement added that Folger is also nursing "a damaged nerve in the right vocal chords" as a consequence of a practice crash at Aragon.

Michael van der Mark continues as Folger's stand-in for a second race this weekend.