Abstract Details

Maternal 15q duplication syndrome is a neurodevelopmental disorder characterized by motor delays, epilepsy, intellectual disability, and autism spectrum disorder (Lusk et al, 2016). Individuals with isodicentric duplications and epilepsy generally present with a more severe phenotype (DiStefano et al, 2020), though there have been no studies examining longitudinal development.

To examine natural change in cognitive, language and adaptive behavior abilities in children with Dup15q Syndrome over 1-2 years.

As part of a larger study examining the behavioral phenotype within Dup15q Syndrome (DiStefano et al, 2020), 16 participants were evaluated ~24 months apart via direct testing of cognitive development (Mullen Scales of Early Learning [MSEL]) and/or parent report of adaptive behavior (Vineland Adaptive Behavior Scales [VABS]). Analysis focused on two aims:

1) Examine whether participants gained skills, lost skills, or remained consistent over time. 

2) Determine whether epilepsy status or duplication type were associated with skill growth.

1)    12 out of 12 participants tested showed skill growth in at least one domain on the MSEL, compared to 9 out of 13 participants on the VABS. Of the domains, gross motor was comparative across both assessments: On MSEL, 7 out of 8 children with gross motor testing gained skills, 1 showed loss of skills. On VABS, 6 out of 8 children gained skills, 2 children showed loss.

2)    Of 7 children who gained skills in the gross motor domain in MSEL, 3 had epilepsy; across all MSEL domains, 58% of positive growth was seen among patients without epilepsy

Our sample suggests that MSEL may be more sensitive to change than VABS in children with Dup15q Syndrome.  The fact that fewer children with epilepsy showed positive growth than children without epilepsy is consistent with recent phenotyping research. Larger studies are necessary to further document natural development among subsets of children with Dup15q Syndrome.