Marcus Gunn phenomenon is a rare genetic disorder that is usually present at birth. It is characterized by the movement of one upper eyelid in a rapid rising motion each time the jaw moves. Other eye abnormalities and vision difficulties may also occur. The exact cause of this phenomenon is not known.

In most patients with Marcus Gunn phenomenon, the upper eyelid of one eye (unilateral) droops (blepharoptosis). The major symptom of this disorder is the rapid and involuntary upward movement of the affected eyelid after almost any movement of the lower jaw. As a result, that eye appears to open even wider. This first becomes apparent soon after birth, especially during feeding and sucking. These activities cause the eyelid to move up and down. A few cases have been seen in adults.

Individuals with Marcus Gunn phenomenon may experience visual impairment, such as crossing of the eyes (strabismus), slight impairment of vision in one eye as compared to the other (a difference in the refractive powers of the eyes [anisometropia], and other problems (e.g., superior rectus muscle palsy or double elevator palsy).

In some cases, symptoms may be produced by movement of the lips, whistling, smiling, clenching the teeth, chewing, puffing out the cheeks, or swallowing.

The exact cause of Marcus Gunn phenomenon is not known. For reasons that are unclear, there is a bad connection between the nerves that stimulate, and the muscles that move, the eyelids and the jaw. Some clinical researchers believe that about half of the cases of Marcus Gunn phenomenon are genetically determined. The site and nature of the gene(s) at fault in this disorder are not known, but familial studies indicate that it is transmitted as an autosomal dominant trait.

Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome and females have two X chromosomes. Each chromosome has a short arm designated p and a long arm designated q. Chromosomes are further sub-divided into many bands that are numbered. For example, chromosome 11p13 refers to band 13 on the short arm of chromosome 11. The numbered bands specify the location of the thousands of genes that are present on each chromosome.

Genetic diseases are determined by the combination of genes for a particular trait which are on the chromosomes received from the father and the mother.

Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.

Treatment of Marcus Gunn phenomenon is usually not needed because the condition tends to grow less noticeable with age. Genetic counseling may be of benefit for patients and their families. Other related eye problems such as strabismus, amblyopia, etc., may be corrected with eyeglasses, surgery and/or drugs.

Surgical correction of the droopiness of the eyelid or of the jaw winking is recommended only if the patient (or parents) agree on which of the symptoms is the more cosmetically objectionable. Surgical procedures are available for several different intensities of the droop of the eyelids.

Marcus gunn (jaw-winking) syndrome is one of the congenital cranial dysinnervation disorders (CCDD) and those with this condition show varying degrees of blepharoptosis in the primary, resting position. It is connected to synkinetic movements of the upper eyelid that occur while the jaw is being masticated.

1. Congenital blepharoptosis is associated with Marcus Gunn jaw-winking syndrome (MGJWS). Dr. Robert Marcus Gunn, a Scottish ophthalmologist, initially identified MGJWS in 1883.
2. The first case of this syndrome was a 15-year-old girl who had unilateral ptosis with contraction of the same upper eyelid.
3. Other names for MGJWS include Pterygoid-levator synkinesis, Maxillopalpebral synkinesis, Marcus-Gunn jaw winking phenomena (MGP), Marcus Gunn ptosis, and Marcus Gunn jaw winking trigemino-oculomotor synkinesis.
4. These people exhibit varying degrees of blepharoptosis in the supine, resting posture, and it is one of the congenital cranial dysinnervation disorders (CCDD).

Complication

1. Under-correction, over-correction, lagophthalmos, suture granuloma, sling slippage, sling extrusion, asymmetric lid crease, and exposure keratitis are among the side effects of ptosis surgery. 2. According to reports, amblyopia affects 30% to 60% of MGJWS.

Pearl and other issues

1. Children with MGJWS should regularly test their eyesight to detect amblyopia earlier and treat it appropriately.
2. Even though they are incredibly uncommon, all known ocular and systemic correlations with Marcus Gunn jaw-winking syndrome (MGJWS) must be ruled out.
3. Prior to doing ptosis surgery on these patients, it is essential to correct their amblyopia and strabismus.
4. Surgery may not be required for all children because some have been reported in the literature to be able to change the position of their jaw, which lessens the degree of ptosis in primary gaze.

Symptoms
Rapid and reflexive upward movement of the afflicted eyelid following nearly any movement of the lower jaw is the main sign of this condition resulting in the widening of eyes
Conditions
Lagophthalmos,Suture granuloma,Slippage of the sling,Extrusion of the sling,Asymmetric lid crease,Exposure keratitis
Drugs
Surgery

There is no cure available for Marcus Gunn (Jaw winking) syndrome (MGJWS).

Treatments include:

Marcus Gunn jaw-winking syndrome (MGJWS) therapy possibilities include the following:

1. Health Care: If amblyopia is discovered, the patient needs vigorous treatment with occlusion therapy and/or correction of anisometropia before considering ptosis surgery. Close monitoring is typically advised while the patient is receiving amblyopia treatment. Monitoring patients can be aided by clinical pictures.

2. Surgical Care: Surgery for MGJWS is currently a contentious topic of discussion. According to some doctors, a child shouldn't undergo surgery until they are one to two years old since general anesthesia is safer at that age than it is during infancy. Any surgical treatment that just addresses the ptosis without addressing the synkinetic winking of the jaw may exacerbate the patient's aberrant eyelid movement, which could be disfiguring from a cosmetic standpoint. Amblyopia, vertical strabismus, severe ptosis with levator muscle failure, and severe ptosis with normal levator function are all indications for surgery.

Symptoms
Rapid and reflexive upward movement of the afflicted eyelid following nearly any movement of the lower jaw is the main sign of this condition resulting in the widening of eyes
Conditions
Lagophthalmos,Suture granuloma,Slippage of the sling,Extrusion of the sling,Asymmetric lid crease,Exposure keratitis
Drugs
Surgery