Marcus Gunn jaw-winking syndrome (MGJWS)

Marcus Gunn jaw-winking syndrome (MGJWS) is noted in congenital blepharoptosis. MGJWS was first described by a Scottish ophthalmologist Dr.Robert Marcus Gunn in the year 1883. This syndrome was initially reported in a 15-year-old girl as unilateral ptosis associated with the upper eyelid contraction on the same side. Other names of MGJWS include Marcus-Gunn jaw winking phenomenon (MGP), Marcus Gunn ptosis, Marcus Gunn jaw winking trigemino-oculomotor synkinesis, Maxillopalpebral synkinesis, and Pterygoid-levator synkinesis. It is one of the congenital cranial dysinnervation disorders (CCDD), and these individuals have variable degrees of blepharoptosis in the resting, primary position.
It is associated with synkinetic movements of the upper eyelid during masticating movements of the jaw. It is usually unilateral but may present bilaterally also.
The occurrence of a coordinated sequence of movements of the muscles innervated by different branches of the same nerve or different nerve is known as synkinesis. In MGJWS, there occurs a coordinated synkinetic movement of the upper eyelid and the jaw as a result of an abnormal connection between the motor branches of the trigeminal nerve and superior division of oculomotor nerve. This is a congenital condition, and the abnormal neurological connection is postulated as fibers of the fifth cranial nerve are responsible for either directly or indirectly innervating the levator muscle. Familial cases with autosomal dominant inheritance have been described in the literature, but are exceedingly rare. There have been few published reports on acquired MGJWS presumed to develop after complicated ocular surgery and trauma.
Approximately 50% of the blepharoptosis cases are congenital. The incidence of MGJWS among individuals with congenital ptosis is approximately 2% to 13%. Although present at birth, MGJWS can occur at a wide range of ages. Bilateral cases have been reported, but mostly MGJWS are unilateral and occurs more frequently on the left. There is no gender predisposition, and males and females are affected equally.