What are the other Names for this Condition? (Also known as/Synonyms)

• Cogan's Syndrome Type 2
• Congenital Oculomotor Apraxia (COMA)
• Congenital Saccade Initiation Failure

What is Oculomotor Apraxia, Cogan Type? (Definition/Background Information)

• Oculomotor Apraxia, Cogan Type (or COMA) is an eye condition characterized by a defect in side-to-side (horizontal) eye movements. Because of this, most patients with COMA have to turn their head in order to follow objects in side gaze. Typically, up-to-down (vertical) eye movements are unaffected
• Symptoms usually improve throughout the childhood and teenage years. COMA can also be associated with mild developmental delay and speech difficulties
• Individuals with COMA may also have kidney disorders and underdevelopment of the part of cerebellum that separates the left and right hemisphere of the brain (cerebellar vermis)
• When other symptoms occur, COMA may be a symptom of other disorders, such as nephronophthisis or Joubert syndrome
• In many instances, the cause of COMA is not known; however, researchers suspect that it is inherited in an autosomal recessive inheritance pattern
• Treatment for this condition is focused on managing the signs and symptoms in each individual

(Source: Oculomotor Apraxia, Cogan Type; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Oculomotor Apraxia, Cogan Type? (Age and Sex Distribution)

• Oculomotor Apraxia, Cogan Type is a rare congenital disorder. The presentation of symptoms may occur at birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Oculomotor Apraxia, Cogan Type? (Predisposing Factors)

• A positive family history may be an important risk factor, since Oculomotor Apraxia, Cogan Type may be inherited

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Oculomotor Apraxia, Cogan Type? (Etiology)

• The exact underlying cause of Oculomotor Apraxia, Cogan Type is currently unknown
• Some researchers believe that it may be inherited in an autosomal recessive manner

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Oculomotor Apraxia, Cogan Type?

The signs and symptoms of Oculomotor Apraxia, Cogan Type varies, but may include:

• Horizontal opticokinetic nystagmus (involuntary and rapid eyeball movement)
• Jerky head movements
• Oculomotor apraxia (when the eye muscles are affected, due to CNS damage)

(Source: Oculomotor Apraxia, Cogan Type; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Oculomotor Apraxia, Cogan Type Diagnosed?

Oculomotor Apraxia, Cogan Type is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Oculomotor Apraxia, Cogan Type?

The complications of Oculomotor Apraxia, Cogan Type may include:

• Kidney abnormalities affecting kidney function
• Brain abnormalities affecting brain function

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Oculomotor Apraxia, Cogan Type Treated?

• Unfortunately, there is no cure for Oculomotor Apraxia, Cogan Type.
• Treatment is focused on managing symptoms
• Specialists that may be involved in the care of an individual with COMA include a nephrologist (kidney specialist), ophthalmologist (eye doctor), geneticist, and neurologist

(Source: Oculomotor Apraxia, Cogan Type; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How can Oculomotor Apraxia, Cogan Type be Prevented?

Currently, Oculomotor Apraxia, Cogan Type is not preventable, since it may be a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Oculomotor Apraxia, Cogan Type? (Outcomes/Resolutions)

• The prognosis of Oculomotor Apraxia, Cogan Type is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Oculomotor Apraxia, Cogan Type:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/diseases-conditions/rare-disorders/