Clinical features
The syndrome caused by mutations in the DYRK1A gene is a multisystem disorder characterized by several features:
- All individuals show mild-severe ID. In approximately 2/3 of individuals a moderate to severe ID is present.
- Autism spectrum disorder (ASD) is frequently diagnosed in individuals with a DYRK1A mutation. Behaviour is often characterised by stereotypic and anxious behaviour and sleep disturbances are common.
- Many individuals don’t speak or use short word sentences. Expressive language is more severely affected compared to receptive language.
- Almost all individuals have feeding problems in infancy. Later in life feeding problems may persist and many individuals are known with a slender build.
- The majority shows typical facial features including a small head circumference, deep-set eyes, mild upslanting palpebral fissures, a short nose with a prominent tip, and a receding broad chin.
- Febrile seizures in childhood occur frequently. Epilepsy is present in a minority at adult age.
- Many individuals show gait disturbances and an increased tightness of muscle tone (hypertonia).
- In a small subset of individuals various eye abnormalities have been observed, such as vision abnormalities, strabismus, early cataract, microphthalmia, retinal dystrophy, optic atrophy, coloboma and retinal detachment.
- Also endocrine anomalies and cardiac anomalies such as left heart hypopasia, septum defects and pulmonic and aortic valve abnormalities have been noted.
Prevalence
Based on current information the prevalence is estimated 1:200-1000 in individuals with an intellectual disability.
Inheritance
The syndrome caused by mutations in the DYRK1A gene is inherited in an autosomal dominant manner.