This is a summary of the clinical characteristics of affected individuals with a confirmed diagnosis of PADDAS:
- Global developmental delay/ Intellectual disability. All affected individuals with PADDAS reported to date have had some degree of motor and/or cognitive delay. This can range from mild to severe. Delay in the acquisition of speech and language is particularly noted. Some individuals are able to talk fluently in sentences, whereas for others communication is limited to a few words, or to alternative communication methods such as picture exchange. Some individuals have dysarthria.
- Disorders of tone and movement. Low tone in infancy is commonly reported, often with associated delays in the attainment of gross motor milestones. Ataxia is commonly reported. There are some reports of ballismus and evolving spasticity.
- Seizure disorder. Seizure disorders have been reported in about a third of individuals with PADDAS and range from well-controlled epilepsy to more severe seizure disorders starting in early childhood.
- Changes in neuroimaging. Not all individuals with PUM1-related disorder have had a brain MRI or CT. Of those who have had imaging, some show neuroanatomical abnormalities such as cortical atrophy, thinning of the corpus callosum and cerebellar hypoplasia.
- Other physical conditions. The majority of individuals with PUM1-related disorder are reported to be otherwise physically healthy. A minority have additional features such as undescended testes (cryptorchidism), ptosis, and ‘squaring’ of the facial features, but most affected individuals resemble their unaffected family members.
The clinical characteristics of affected individuals with a confirmed diagnosis of PRCA are so far consistent with a pure cerebellar ataxia. In the sole family with affected individuals, gait abnormalities have variable onset from the 30’s to the 50’s and are accompanied by other cerebellar signs such as dysmetria, dysarthria, and, in some cases, diplopia. Some of these affected individuals have had MRI studies revealing mild cerebellar vermian atrophy. Affected individuals in this family are otherwise healthy and have normal intelligence.