The broad phenotypic spectrum of PPP2R1A-related neurodevelopmental disorders correlates with the degree of biochemical dysfunction

Genet Med. 2021 Feb;23(2):352-362. doi: 10.1038/s41436-020-00981-2. Epub 2020 Oct 27.


Purpose: Neurodevelopmental disorders (NDD) caused by protein phosphatase 2A (PP2A) dysfunction have mainly been associated with de novo variants in PPP2R5D and PPP2CA, and more rarely in PPP2R1A. Here, we aimed to better understand the latter by characterizing 30 individuals with de novo and often recurrent variants in this PP2A scaffolding Aα subunit.

Methods: Most cases were identified through routine clinical diagnostics. Variants were biochemically characterized for phosphatase activity and interaction with other PP2A subunits.

Results: We describe 30 individuals with 16 different variants in PPP2R1A, 21 of whom had variants not previously reported. The severity of developmental delay ranged from mild learning problems to severe intellectual disability (ID) with or without epilepsy. Common features were language delay, hypotonia, and hypermobile joints. Macrocephaly was only seen in individuals without B55α subunit-binding deficit, and these patients had less severe ID and no seizures. Biochemically more disruptive variants with impaired B55α but increased striatin binding were associated with profound ID, epilepsy, corpus callosum hypoplasia, and sometimes microcephaly.

Conclusion: We significantly expand the phenotypic spectrum of PPP2R1A-related NDD, revealing a broader clinical presentation of the patients and that the functional consequences of the variants are more diverse than previously reported.

Keywords: PP2A; PPP2R1A; epilepsy; intellectual disability; neurodevelopmental disorder.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Intellectual Disability* / genetics
  • Microcephaly*
  • Muscle Hypotonia
  • Neurodevelopmental Disorders* / epidemiology
  • Neurodevelopmental Disorders* / genetics
  • Protein Phosphatase 2 / genetics
  • Transcription Factors


  • PPP2R1A protein, human
  • PPP2R5D protein, human
  • Transcription Factors
  • PPP2CA protein, human
  • Protein Phosphatase 2