Parent-Infant Interaction in Infants with Neurofibromatosis Type 1

Background: Neurofibromatosis Type 1 (NF1) is a single gene autosomal dominant syndromic model of autism with a prevalence of 1 in 3000 with well described neurobiology in animal models . Unlike ASD, NF1 can be diagnosed in infancy using cord blood testing for mutations in affected families .. A recent case series describes the first developmental profiles of infants with NF1 and reports delayed or impaired motor and communicative skills in all cases relative to infants at high familial risk who were subsequently diagnosed with ASD (as well as high-risk infants that were typically developing and low-risk controls). Since infants who are later diagnosed with ASD show parent-infant interactions that diverge from those seen in typical development from around 9-10 months of age, infants with NF1 may show further divergence in such interactions, with implications for their social and communicative development.

Objectives: As part of the prospective Early Development in Neurofibromatosis Type 1 (EDEN) project, we examined the interactions of 12 ten to 11-month-old infants with NF1 with their parents. The aims are: (1) to describe their parent-infant interactions, (2) to compare their interactions to those of high-risk infants with later ASD (from the British Autism Study of Infant Siblings; BASIS), high-risk infants with typical development, and low-risk infants; (3) to explore the associations between the parent-infant interactions of infants with NF1 and concurrent motor, communicative, social and cognitive functioning.

Methods: The validated Manchester Assessment of Caregiver-Infant Interaction (MACI) is a global measure used to evaluate seven areas of interaction. Evaluations of 6-min videotaped unstructured play interaction were made by two independent trained coders blind to all family information. The Mullen Scales of Early Development and Vineland Adaptive Behavior Scale (Parent Form) were completed as part of a battery of assessments.

Results: The parent-infant interactional styles of these infants will be described, highlighting how high object (toy) interest and low attentiveness to parent seem to have differential impacts on parental response that affect the infant’s social experience. Aspects of parent-infant interaction were correlated with their concurrent motor and communicative scores, but not their social and cognitive scores. We will report on group differences in MACI (parent-infant interaction) ratings.

Conclusions: Our findings are consistent with the interpretation that the early emergence of motor and communicative difficulties in infants with NF1 impact social interactions with their parents in specific ways that may reduce the social opportunities, which are important for their communicative and social development. Furthermore, unlike infants at familial risk of ASD, who have at least one older sibling, these infants do not necessarily have a sibling. Thus, these early findings may be taken as support for altered parent-infant interaction being the result of the emergence of early neurodevelopmental markers rather than learned interactive styles (from interacting with the older child in the case of ASD).