Is BCS1L p.Val191= (c.573G>T) pathogenic?

BCS1L p.Val191= (c.573G>T) is classified Uncertain significance in BCS1L (ClinVar, Single submitter, 1 submitter; last evaluated 2024-06-01). Absent from gnomAD v4.1; Associated with mitochondrial complex III deficiency nuclear type 1.

How common is BCS1L p.Val191= (c.573G>T) in the general population?

BCS1L p.Val191= (c.573G>T) is absent from gnomAD v4.1 (gnomAD).

BCS1L p.Val191=

Q: What condition is associated with BCS1L p.Val191= (c.573G>T)?

BCS1L p.Val191= (c.573G>T) is associated with mitochondrial complex III deficiency nuclear type 1, Bjornstad syndrome, GRACILE syndrome (ClinVar).

c.573G>T · VCV3585649

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

mitochondrial complex III deficiency nuclear type 1

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation/SpliceAI carries the signal.
Splicing
SpliceAI	Δ0.41	acceptor gain · deltas
Pangolin	Δ0.33	gain · loss 0.00 · agrees with SpliceAI · independent
Constraint at this position
Conservation	phyloP 2.1	GERP -0.77, phastCons 1
Overall
CADD	15.73	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: BCS1L
Protein: p.Val191=
Coding: c.573G>T
MANE Select: NM_001079866
Type: single nucleotide variant
Location: chr2:218661871 (GRCh38)
Gene constraint: LOEUF 0.958 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 87.10

Full BCS1L gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

mitochondrial complex III deficiency nuclear type 1 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: Bjornstad syndrome GRACILE syndrome

Similar variants

BCS1L c.320+1G>T Pathogenic/Likely pathogenic ★★ same condition
BCS1L c.321-2A>G Likely pathogenic ★★ same condition
BCS1L c.889+1G>T Pathogenic/Likely pathogenic ★★ same condition
BCS1L c.889+2T>G Likely pathogenic ★★ same condition
BCS1L c.-50+388C>G Likely pathogenic ★★ same condition
BCS1L c.-50+405A>G Pathogenic/Likely pathogenic ★★ same condition
BCS1L p.Arg109Trp Pathogenic/Likely pathogenic ★★ ⚠ same condition
BCS1L p.Arg114Trp Pathogenic/Likely 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/bcs1l-p-val191 (accessed [today's date]).

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