32193
Language and Motor Development in Children with Adnp Syndrome
Activity-Dependent Neuroprotector Homeobox Protein (ADNP) is a transcription factor-encoding gene located on chromosome 20. ADNP Syndrome is a rare neurodevelopmental disorder caused by mutations and deletions in the ADNP gene and has been identified as one of the more common single-gene causes of autism spectrum disorder (ASD). ADNP syndrome has also been associated with intellectual disability and global developmental delay encompassing both language and motor domains.
Objectives:
To comprehensively characterize language and motor development in children with ADNP syndrome.
Methods:
Ten children with ADNP syndrome (4 female, ages 3-12 years) were evaluated using standardized assessments including the Mullen Scales of Early Learning, the Expressive Vocabulary Test, Second Edition (EVT-2), the Peabody Picture Vocabulary Test, Fourth Edition (PPVT-4), and the Vineland Adaptive Behavior Scales, Second or Third Edition, Survey Interview Form. Language and motor milestones were collected using the Autism Diagnostic Interview-Revised (ADI-R).
Results:
Language and motor milestones were delayed in all participants. In the language domain, average age of first word and phrase speech were 31 and 60 months, respectively. At the time of evaluation, six participants were nonverbal or minimally verbal, two children used phrase speech, and two children used fluent speech. Seventy-one percent of participants (5/7) who completed the Mullen had higher age equivalents on the receptive language scale (M=22.29, SD=11.66) compared to the expressive language scale (M=19.14, SD=10.24). Of participants able to complete the PPVT-4 and EVT-2 (n=6), 67% scored higher on tasks of receptive language (M=60.57, SD=12.54) compared to tasks of expressive language (M=54, SD=14.25). On the Vineland, 70% of caregivers reported their child’s expressive language skills (M=25, SD=14.19) were better developed than receptive language skills (M=22, SD=10.15).
In the motor domain, nine of 10 participants were able to walk unaided. Average age of first crawling and walking was 16 and 25 months, respectively. Of the seven participants who completed the Mullen, 71% (5/7) of participants had higher age equivalents on the Mullen for gross motor (M=25, SD=8.02) than for fine motor development (M=20.86, SD=5.40). Similarly, 71% (5/7) of participants had higher age equivalents on the Vineland for gross motor subdomain (M=26.71, SD=16.77) compared to the fine motor subdomain (M=24.86, SD=16.47).
Conclusions:
Delays in achieving language and motor milestones were reported in all participants. Current scores from standardized clinician-administered assessments indicated better developed receptive language abilities compared to expressive language abilities, despite caregiver report of an opposite profile. Results indicate that children with ADNP syndrome may understand more than they are able to express, which has important implications for behavioral and educational interventions. Both clinician-administered and caregiver interviews revealed better developed gross motor abilities relative to fine motor abilities. Results suggest intensive speech therapy, occupational therapy, and physical therapy are critical for individuals with ADNP syndrome and should be initiated early on.