Neurodevelopmental profile in Angelman syndrome: more than low intelligence quotient

BACKGROUND Angelman Syndrome (AS) is a rare neurodevelopment disorder resulting from deficient expression or function of the maternally inherited allele of UBE3A gene. The aim of the study is to attempt at providing a detailed definition of neurodevelopmental profile in AS, with particular regard to motor, cognitive, communicative, behavioural and neurovisual, features by using standardized instruments. METHOD A total of ten subjects aged from 5 to 11 years (4 males and 6 females) with molecular confirmed diagnosis of AS (7 15q11.2-q13 deletion and 3 UBE3A mutation) were enrolled in our study. All of them underwent an assessment protocol including neurological and neurovisual examination and the evaluation of motor (Gross Motor Function Measure Scale), cognitive (Griffiths Mental Development Scale and Uzgiris-Hunt Scale); adaptive (Vineland Adaptive Behavioural Scale); communication (MacArthur-Bates Communicative Development Inventory and video-recordings children's verbal expression), behavioural aspects (IPDDAG Scale) and neurovisual aspects. RESULTS All children presented motor function involvement. A severe cognitive impairment was detected with different profiles according to the test applied. In all cases, communicative disability (phonemic inventory, word/gesture comprehension and production) and symptoms of inattention disorder were revealed. Neurovisual impairment was characterized by refractive errors, fundus oculi anomalies, strabismus and/or oculomotor dysfunction. CONCLUSION AS presents a complex neurodevelopmental profile in which several aspects play a negative role in global development leading to a severe functional impairment. Intellectual disability is not the only component because neurovisual functions and behavioural disorders may worsen the global function and are needed of specific rehabilitation programs.