MedGen

Spinocerebellar ataxia type 6 (SCA6) is characterized by adult-onset, slowly progressive cerebellar ataxia, dysarthria, and nystagmus. The age of onset ranges from 19 to 73 years; mean age of onset is between 43 and 52 years. Initial symptoms are gait unsteadiness, stumbling, and imbalance (in ~90%) and dysarthria (in ~10%). Eventually all persons have gait ataxia, upper-limb incoordination, intention tremor, and dysarthria. Dysphagia and choking are common. Visual disturbances may result from diplopia, difficulty fixating on moving objects, horizontal gaze-evoked nystagmus, and vertical nystagmus. Hyperreflexia and extensor plantar responses occur in up to 40%-50%. Basal ganglia signs, including dystonia and blepharospasm, occur in up to 25%. Mentation is generally preserved. [from GeneReviews]

Classic congenital or infantile nystagmus presents as conjugate, horizontal oscillations of the eyes, in primary or eccentric gaze, often with a preferred head turn or tilt. Other associated features may include mildly decreased visual acuity, strabismus, astigmatism, and occasionally head nodding. Eye movement recordings reveal that infantile nystagmus is predominantly a horizontal jerk waveform, with a diagnostic accelerating velocity slow phase. However, pendular and triangular waveforms may also be present. The nystagmus may rarely be vertical. As these patients often have normal visual acuity, it is presumed that the nystagmus represents a primary defect in the parts of the brain responsible for ocular motor control; thus the disorder has sometimes been termed 'congenital motor nystagmus' (Tarpey et al., 2006; Shiels et al., 2007). For a discussion of genetic heterogeneity of congenital nystagmus, see NYS1 (310700). [from OMIM]

Constant esotropia occurring before 6 months of age. It is typically associated with a large angle of deviation, alternating fixation (therefore low risk of amblyopia) and poor potential for binocular single vision. Other features that might be present in individuals with infantile (constant) esotropia include latent nystagmus or manifest latent nystagmus, dissociated vertical divergence, cyclotropia, abnormal head posture, limited abduction. [from HPO]

A facial cleft extending from the zygomatic arch to the eye. This zygomaticomaxillary cleft is similar to that typically found in Treacher Collins syndrome. The overlying tissue shows a vertical sclerodermic furrow radiating from the labial commissure or the angle of the mandible across the cheek to a coloboma of the lower eyelid between the middle and lateral one-third. Microphthalmia is not observed. The skeletal cleft is between the maxilla and zygoma; it passes through the inferolateral orbital rim to enter the inferior orbital fissure. No alveolar cleft is present. The zygomatic arch is intact. The soft tissue furrow, which is more apparent on the right, radiates from the oral commissure toward the lateral two-thirds of the lower eyelid. The antimongoloid obliquity of the palpebral fissures is associated with laterally placed lower eyelid clefts and some ectropion. A left-sided anophthalmia is accompanied by adjacent soft tissue hypoplasia and is reflected in a short palpebral fissure, enophthalmos, and minor ptosis of the eyebrow. No abnormality is present in the alveolar arch except for some tilting of the occlusal plane secondary to hypoplasia of the left side of the maxilla. There is a vertical bony groove in the region of the zygomaticomaxillary suture that ends in the inferolateral portion of a small bony orbit. More laterally, the remainder of the zygomatic body and arch is normal in both shape and dimension. The lateral orbital floor is downslanting but intact, and it lacks direct communication with the temporal or infratemporal fossae. The hypoplasia of the left side of the maxilla and orbit is associated with a reduction in the transverse and anteroposterior dimensions of the anterior cranial fossa; mild asymmetry of the middle cranial fossa and calvarium is present. No significant asymmetry of size, shape, or position is present in the sphenoid. [from HPO]

A rare genetic multiple congenital anomalies/dysmorphic syndrome with the association of severe intellectual disability, strabismus and anterior maxillary protrusion with vertical maxillary excess, open bite and prominent crowded teeth. Mild cochlear hearing loss has been reported in addition. [from SNOMEDCT_US]