RPS6KA3

Chr XXLD

ribosomal protein S6 kinase A3

Also known as: CLS, HU-3, ISPK-1, MAPKAPK1B, MRX19, RSK, RSK2, S6K-alpha3

This serine/threonine kinase acts downstream of ERK signaling to regulate transcription factors, translation initiation, and cellular proliferation and survival pathways. Mutations cause Coffin-Lowry syndrome and X-linked intellectual developmental disorder, with X-linked dominant inheritance affecting both males and females but typically more severely in males. The gene is highly constrained against loss-of-function variants (pLI = 1.0, LOEUF = 0.087), consistent with its essential role in cellular signaling pathways.

OMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismXLDLOEUF 0.092 OMIM phenotypes
Clinical SummaryRPS6KA3
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Gene-Disease Validity (ClinGen)
Coffin-Lowry syndrome · XLDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 1.00). One damaged copy is likely sufficient to cause disease.
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Clinical Trials
1 active or recruiting trial — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Dual constrained — LoF & missense intolerant
LoF Constraint
0.09LOEUF
pLI 1.000
Z-score 5.41
OE 0.00 (0.000.09)
Highly constrained

Among the most LoF-intolerant genes (~top 3%)

Missense Constraint
4.52Z-score
OE missense 0.23 (0.190.29)
64 obs / 275.0 exp
Constrained

Highly missense-constrained (top ~0.1%)

Observed / Expected Ratios
LoF OE0.00 (0.000.09)
00.351.4
Missense OE0.23 (0.190.29)
00.61.4
Synonymous OE0.81
01.21.6
LoF obs/exp: 0 / 34.1Missense obs/exp: 64 / 275.0Syn Z: 1.41
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveRPS6KA3-related Coffin-Lowry syndromeLOFmonoallelic_X_heterozygous
DN
0.3793th %ile
GOF
0.5269th %ile
LOF
0.71top 10%

The highest-scoring mechanism for this gene is loss-of-function (haploinsufficiency).

LOFprediction above median · LOEUF 0.09

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

RPS6KA3 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold
Clinical Literature
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