Is CBS p.Cys165= (c.495C>T) pathogenic?

CBS p.Cys165= (c.495C>T) is classified Likely benign in CBS (ClinVar, Single submitter, 1 submitter; last evaluated 2023-12-28). Absent from gnomAD v4.1; Associated with HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED.

What condition is associated with CBS p.Cys165= (c.495C>T)?

CBS p.Cys165= (c.495C>T) is associated with HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED (ClinVar).

How common is CBS p.Cys165= (c.495C>T) in the general population?

CBS p.Cys165= (c.495C>T) is absent from gnomAD v4.1 (gnomAD).

CBS p.Cys165=

c.495C>T · rs2517447435 · VCV2706245

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED

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 0.85	GERP -0.98, phastCons 0.85
Overall
CADD	9.154	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: CBS
Protein: p.Cys165=
Coding: c.495C>T
MANE Select: NM_000071
dbSNP: rs2517447435
Type: single nucleotide variant
Location: chr21:43065652 (GRCh38)
Structure: AlphaFold pLDDT 90.15 · 28 PDB
Residue 165: a β-strand; a UniProt-annotated variant site (in cbsd; severe form; protein expression is comparable to wild-type; loss of cystathionine beta-synthase activity; no effect on homotetramer formation)

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

Disease context

HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

CBS p.Cys165Gly Pathogenic ★ ⚠ same residue
CBS p.Cys165Tyr Pathogenic ★★ same residue
CBS c.1145+1G>A Pathogenic/Likely pathogenic ★★ same condition
CBS c.1223+1G>T Pathogenic ★★ same condition
CBS c.1552+1G>A Pathogenic/Likely pathogenic ★★ same condition
CBS c.451+1G>T Likely pathogenic ★★ same condition
CBS c.531+1G>A Likely pathogenic ★★ same condition
CBS c.736+2T>G 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/cbs-p-cys165 (accessed [today's date]).

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