Features include always present findings: Delayed speech and language development, Motor delay, and Intellectual disability; and common findings: Upslanted palpebral fissure, Strabismus, Low muscle tone (hypotonia), and Malar flattening and others. 14 total HPO annotations.

DLG3 encodes discs large MAGUK scaffold protein 3 (817 aa). Required for learning most likely through its role in synaptic plasticity following NMDA receptor signaling Highest expression in Brain Cerebellar Hemisphere (32.3 TPM) and Brain Cerebellum (27.0 TPM).

Intellectual disability, X-linked 90 is associated with mutations in the DLG3 gene on chromosome X.

The DLG3 protein participates in GluN1:GluN2 (GRIN1:GRIN2) NMDA receptors traffic to the plasma membrane, GluN1:GluN2 (GRIN1:GRIN2) NMDA receptors bind to postsynaptic density proteins, and SALMs 1-3 bind to PSD-95 family members pathways.

DLG3 is classified as a druggable target (Kinase category) with score 0.0.

Genetic testing for DLG3 is available. Testing is considered confirmatory for diagnosis.

Biomarker and diagnostic research for intellectual disability, X-linked 90 has been reported in the published literature.

Phenotype severity distribution: 3 always present features, 8 common features.

No clinical trials have been registered for intellectual disability, X-linked 90.

35 publications have been identified in PubMed for intellectual disability, X-linked 90. Research spans Case Report / Case Series (26%), Basic Science / Preclinical (26%), and Epidemiology / Natural History (26%).