Is SRCAP p.Arg940Trp (c.2818C>T) pathogenic?

SRCAP p.Arg940Trp (c.2818C>T) is classified Uncertain significance in SRCAP (ClinVar, Single submitter, 1 submitter; last evaluated 2024-06-22). AlphaMissense: likely benign (0.2789); Very rare (popmax 0.00111%, sas); Associated with developmental delay, hypotonia, musculoskeletal defects, and behavioral abnormalities.

How common is SRCAP p.Arg940Trp (c.2818C>T) in the general population?

SRCAP p.Arg940Trp (c.2818C>T) is very rare (popmax 0.00111%, sas) (gnomAD).

What do computational predictors say about SRCAP p.Arg940Trp (c.2818C>T)?

AlphaMissense predicts likely benign (score 0.2789) — an in-silico prediction, not a clinical call.

SRCAP p.Arg940Trp

Q: What condition is associated with SRCAP p.Arg940Trp (c.2818C>T)?

SRCAP p.Arg940Trp (c.2818C>T) is associated with developmental delay, hypotonia, musculoskeletal defects, and behavioral abnormalities, Floating-Harbor syndrome (ClinVar).

c.2818C>T · VCV3580100

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.2789 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00111%, sas)

Conditions

developmental delay, hypotonia, musculoskeletal defects, and behavioral abnormalities

Computational evidence

Protein change
AlphaMissense	0.2789	likely benign
REVEL	0.61	indeterminate
SaProt	—	not scored · why
Splicing
SpliceAI	<0.2	all four deltas below 0.2 · C>G here scores Δ0.24 · evaluated, not missing
Constraint at this position
Conservation	phyloP 2.8	GERP 0.72, phastCons 1
Regional constraint	o/e 0.69	unconstrained · MANE · 4,608 bp · p 6.7e-06 · regional, not allelic
Overall
CADD	25.7	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL is an independent agreement signal.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00111% South Asian · 1/90,464 alleles

Overall 0.000313% 5/1,599,424 alleles · very rare exomes 4/1,447,278 · genomes 1/152,146 · joint denominator

Ancestry group	Frequency	1 in
Remaining individualsnot grpmax-eligible	0.00485%	20,629
South Asiangrpmax	0.00111%	90,464
European (non-Finnish)	8.56e-05%	1,168,344

Remaining individuals shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: SRCAP
Protein: p.Arg940Trp
Coding: c.2818C>T
MANE Select: NM_006662
Type: single nucleotide variant
Location: chr16:30720162 (GRCh38)
Gene constraint: LOEUF 0.223 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Residue 940: a UniProt-annotated variant site (in dehmba)

Full SRCAP gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

developmental delay, hypotonia, musculoskeletal defects, and behavioral abnormalities — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: Floating-Harbor syndrome

Similar variants

SRCAP p.Arg940Gln Conflicting classifications of pathogenicity ★ ⚠ same residue
SRCAP p.Arg2329Ter Pathogenic/Likely pathogenic ★★ same condition
SRCAP p.Arg2435Ter Pathogenic/Likely pathogenic ★★ same condition
SRCAP p.Arg2444Ter Pathogenic ★★ same condition
SRCAP p.Arg2718Ter Pathogenic/Likely pathogenic ★★ same condition
SRCAP p.Arg2748Ter Pathogenic ★★ same condition
SRCAP p.Gln2407Ter Pathogenic ★★ same condition
SRCAP p.Gln2419Ter Pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/srcap-p-arg940trp (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown