Clinical characteristics, longitudinal adaptive functioning, and association with electroencephalogram activity in PPP2R5D-related neurodevelopmental disorder

Clin Genet. 2025 Jan;107(1):34-43. doi: 10.1111/cge.14612. Epub 2024 Aug 21.

Abstract

Protein phosphatase 2 regulatory subunit B56δ related neurodevelopmental disorder (PPP2R5D-related NDD) is largely caused by de novo heterozygous missense PPP2R5D variants. We report medical characteristics, longitudinal adaptive functioning, and in-person neurological, motor, cognitive, and electroencephalogram (EEG) activity for PPP2R5D-related NDD. Forty-two individuals (median age 6 years, range = 0.8-25.3) with pathogenic/likely pathogenic PPP2R5D variants were assessed, and almost all variants were missense (97.6%) and de novo (85.7%). Common clinical symptoms were developmental delay, hypotonia, macrocephaly, seizures, autism, behavioral challenges, and sleep problems. The mean Gross motor functional measure-66 was 60.2 ± 17.3% and the mean Revised upper limb module score was 25.9 ± 8.8. The Vineland-3 adaptive behavior composite score (VABS-3 ABC) at baseline was low (M = 61.7 ± 16.8). VABS-3 growth scale value scores increased from baseline in all subdomains (range = 0.6-5.9) after a mean follow-up of 1.3 ± 0.3 years. EEG beta and gamma power were negatively correlated with VABS-3 score; p < 0.05. Individuals had a mean Quality-of-life inventory-disability score of 74.7 ± 11.4. Twenty caregivers (80%) had a risk of burnout based on the Caregiver burden inventory. Overall, the most common clinical manifestations of PPP2R5D-related NDD were impaired cognitive, adaptive function, and motor skills; and EEG activity was associated with adaptive functioning. This clinical characterization describes the natural history in preparation for clinical trials.

Keywords: PPP2R5D; adaptive function; autism; behavioral problems; developmental delay; electroencephalogram (EEG); macrocephaly; neurodevelopmental disorder; seizure.

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Electroencephalography*
  • Female
  • Humans
  • Infant
  • Male
  • Neurodevelopmental Disorders* / genetics
  • Neurodevelopmental Disorders* / physiopathology
  • Phenotype
  • Protein Phosphatase 2* / genetics
  • Young Adult

Substances

  • Protein Phosphatase 2
  • PPP2R5D protein, human