The following description of the clinical spectrum is based on the Skraban et al., AJHG 2017.
Intellectual disability and developmental delay have been described all in reported individuals with SKDEAS. The average age of walking is approximately 2 years. Language is typically more significantly affected, with several individuals remaining nonverbal.
In general, individuals typically have a happy and friendly demeanor. Autistic and/or repetitive behaviors have been reported in several individuals.
All reported individuals have had some form of seizures including febrile seizures, tonic-clonic, absence, and Rolandic seizures. Fortunately, most epilepsy in these individuals has typically been easy to treat with standard therapy, if indicated. Structural brain anomalies have been noted, but are typically minor, although one individual had a markedly abnormal left hemispheric structure requiring a hemispherectomy.
Hypotonia in infancy and early childhood is common. Differences in gait have commonly been noted including wide-based, ataxic, hemiparetic, and/or stiff-legged gaits.
Recognizable facial features
Common facial features include a prominent maxilla and upper lip, wide mouth, abnormal gingiva, widely spaced teeth, mildly coarse features, broad or full nasal tip, full cheeks in childhood, and subjectively large-appearing irises.
Other reported features include ophthalmologic anomalies (most commonly strabismus and/or amblyopia), minor structural heart defects (right-sided aortic arch, ventricular septal defect), cleft palate, feeding difficulties/failure to thrive, and orthopaedic differences.