Previous symbols: GNAS1. Aliases: NESP55, NESP, GNASXL, GPSA, SCG6, SgVI.
NESP55 (UniProt O95467) is a maternally expressed, chromogranin-like neuroendocrine secretory protein encoded by the complex GNAS locus. NESP55 is distinct from the canonical Gs-alpha products of the same locus; it is expressed in neuroendocrine/chromaffin lineages, processed into smaller peptides, and functions as a regulated secretory-granule precursor and marker of neuroendocrine differentiation. GNAS-locus imprinting defects involving the NESP55 region can cause endocrine disease, but those locus-level effects are distinct from direct NESP55 protein activity.
Relationship is the entry's genetic[].relationship_type. untyped means the entry has a genetic record for the gene but does not type it; its free-text association is shown instead.
| Disorder | Relationship | Where the gene appears |
|---|---|---|
| Adrenal Cortex Adenoma | somatic driver somatic |
mechanism: PRKACA Catalytic Subunit Activation
subtype: Cortisol-Producing
scoped to subtype: Cortisol-Producing
|
| Appendiceal Neoplasm | somatic driver somatic | |
| Fibrous Dysplasia | causative somatic gain of function |
mechanism: Extraskeletal mosaic GNAS activation; Somatic GNAS activation in mosaic skeletal progenitors
subtype: McCune-Albright syndrome
|
| GNAS-related pituitary adenoma 3 | somatic driver somatic gain of function |
mechanism: Constitutive Gs-alpha adenylate cyclase activation; Somatic activating GNAS mutation
diagnosis: Somatotroph tumor GNAS sequencing
|
| Pseudomyxoma Peritonei | somatic driver somatic |
mechanism: KRAS and GNAS Driver Mutations in Appendiceal Mucinous Epithelium
|
| Testicular Sex Cord-Stromal Neoplasm | somatic driver somatic |
mechanism: cAMP/PKA Pathway Activation
subtype: Leydig Cell Tumor
|
| Pseudohypoparathyroidism |
untyped
Loss-of-Function Variant or Imprinting Defect
|
mechanism: GNAS Imprinting-Dependent Signaling Defect
|
| Pseudopseudohypoparathyroidism |
untyped
Heterozygous GNAS coding loss of function on the paternal chromosome; inherited or de novo
|
mechanism: Paternal GNAS coding loss of function
|
| Pituitary Tumor | no genetic record |
mechanism: Clonal Expansion of an Adenohypophyseal Cell Lineage
subtype: Somatotroph
|
Identity from HGNC (snapshot 2026-10-01). Page layers are described in the gene pages documentation.