Itoje suffers broken jaw

England lock Maro Itoje has suffered a broken jaw and could be a doubt for the start of the Six Nations campaign.

Itoje, 23, was injured in a collision with Mike Brown as Saracens lost 20-19 to Harlequins on Sunday at The Stoop. England launch their Six Nations title defence against Italy in Rome on 4 February, leaving Itoje two months to get fit for selection.