Genetic Studies of Strabismus, Congenital Cranial Dysinnervation Disorders (CCDDs), and Their Associated Anomalies

If left untreated or unrecognized, strabismus or misalignment of the eyes, can impair the
development of normal vision and is recognized to be an inherited trait in some families. The
Engle Lab has investigated the genetics of complex and common strabismus and eyelid movement
disorders for over 10 years and the lab's interests have expanded to include Congenital
Cranial Dysinnervation Disorders (CCDDs) which are neurological disorders affecting one or
more of the 12 cranial nerves. Cranial nerves control bodily functions such as movement of
the eyes, transmission of visual information, smell, facial sensation, facial expression,
blinking, hearing, balance, taste, chewing and swallowing.

Based on genetic studies on individuals with eye movement and eyelid disorders, the lab
learned that some individuals have additional ocular defects, vascular, limb and other
abnormalities. In addition, in some families relatives who carry the gene mutation may
manifest the familial syndrome by having only some additional features but NOT the
oculomotility disorder. Therefore, to gain greater understanding of the spectrum of the
disorders being investigated, we may also enroll individuals without eye movement or lid
defects who have symptoms associated with mutations in congenital cranial dysinnervation
disorder (CCDD) genes.

Inclusion Criteria:

- The Engle Lab is very interested in enrolling individuals with congenital conditions
related to eye movement, cranial nerve and brainstem-based dysfunction, often broadly
referred to as congenital cranial dysinnervation disorders (CCDDs).

Exclusion Criteria:

- Individuals with cranial nerve disorders associated with known disorders, such as
Saethre-Chotzen associated with established genetic mutations, or acquired conditions
including trauma, stroke, tumor or spinal cord injuries.