Resources for Medical Professionals

PPP3CA Developmental and Epileptic Encephalopathy (DEE91) is an ultra-rare genetic disorder caused by pathogenic variants in the PPP3CA gene (protein phosphatase 3 catalytic subunit alpha). This gene encodes the catalytic subunit of calcineurin, a calcium-dependent phosphatase highly expressed in the brain that plays a critical role in synaptic vesicle recycling, synaptic plasticity, neuronal development, learning, and memory.

 

Variants in PPP3CA disrupt calcineurin’s normal function, impairing the regulation of neuronal signaling and brain development. This disruption can lead to abnormal network activity, altered connectivity, and epilepsy.

 

Rather than representing strictly separate phenotypes, PPP3CA-related disorders exist along a spectrum. Clinical presentation can vary based on the location and functional impact of the variant—including variants affecting the catalytic domain, regulatory regions, or autoinhibitory domain—but significant overlap exists across individuals.

Common clinical features may include:

• Developmental delay and intellectual disability, often severe

• Epilepsy, often drug-resistant

• Autism spectrum disorder and/or behavioral challenges

• Hypotonia and motor impairment

• Behavioral challenges

• Structural brain abnormalities

• Dysmorphic features and, in some cases, skeletal abnormalities

At a molecular level, PPP3CA variants are generally categorized by their functional effect:​

• Loss of function (LoF): reduced or absent calcineurin activity

• Gain of function (GoF): increased or dysregulated activity, often due to disruption of normal inhibitory control
   

Emerging research suggests that these functional differences may contribute to variability in clinical presentation, though genotype–phenotype relationships are still being defined.

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For the most current medical literature and clinical resources, see the links below:​​

Research Papers