Is CHMP2B p.Ser183= (c.549A>G) pathogenic?

CHMP2B p.Ser183= (c.549A>G) is classified Benign/Likely benign in CHMP2B (ClinVar, Multiple submitters, 2 submitters; last evaluated 2023-11-01). Ultra-rare (popmax 0.056%, afr); Associated with frontotemporal dementia and/or amyotrophic lateral sclerosis 7.

What condition is associated with CHMP2B p.Ser183= (c.549A>G)?

CHMP2B p.Ser183= (c.549A>G) is associated with frontotemporal dementia and/or amyotrophic lateral sclerosis 7 (ClinVar).

How common is CHMP2B p.Ser183= (c.549A>G) in the general population?

CHMP2B p.Ser183= (c.549A>G) is ultra-rare (popmax 0.056%, afr) (gnomAD).

How is Behavioral variant of frontotemporal dementia inherited?

Typically Autosomal dominant (Orphanet). A genetic counselor can assess individual risk for a family.

CHMP2B p.Ser183=

c.549A>G · rs143178463 · VCV346808

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

ultra-rare (popmax 0.056%, afr)

Conditions

frontotemporal dementia and/or amyotrophic lateral sclerosis 7

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 0.017	GERP -5.4, phastCons 0.039
Overall
CADD	4.398	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.056% African / African-American · 42/74,976 alleles

Filtering AF 0.0425% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0379%

Overall 0.00385% 62/1,612,422 alleles · ultra-rare exomes 35/1,460,344 · genomes 27/152,078 · joint denominator

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.056%	1,785
Remaining individualsnot grpmax-eligible	0.0256%	3,901
Middle Eastern	0.0165%	6,056
Admixed American	0.00334%	29,931
European (non-Finnish)	8.48e-05%	1,178,750

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: CHMP2B
Protein: p.Ser183=
Coding: c.549A>G
MANE Select: NM_014043
dbSNP: rs143178463
Type: single nucleotide variant
Location: chr3:87253729 (GRCh38)
Gene constraint: LOEUF 1.503 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 80.26 · 1 PDB
Residue 183: the 'disordered' region

Full CHMP2B gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

frontotemporal dementia and/or amyotrophic lateral sclerosis 7 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Behavioral variant of frontotemporal dementia (Orphanet):

Inheritance: Autosomal dominant
Onset: Adult
Prevalence: 1-9 / 100 000 (Netherlands)

Similar variants

CHMP2B p.Ser183Ter Uncertain significance ★ same residue
CHMP2B c.126+4A>G Uncertain significance ★★ same condition
CHMP2B p.Arg205Gln Uncertain significance ★★ ⚠ same condition
CHMP2B p.Arg205Leu Uncertain significance ★★ ⚠ same condition
CHMP2B p.Arg205Trp Uncertain significance ★★ same condition
CHMP2B p.Arg69Trp Uncertain significance ★★ ⚠ same condition
CHMP2B p.Asn113Lys Uncertain significance ★★ ⚠ same condition
CHMP2B p.Asn143Ser Uncertain significance ★★ ⚠ 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/chmp2b-p-ser183 (accessed [today's date]).

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