Is CYBB p.Ile241Leu (c.721A>C) pathogenic?

CYBB p.Ile241Leu (c.721A>C) is classified Likely benign in CYBB (ClinVar, Single submitter, 1 submitter; last evaluated 2022-07-04). AlphaMissense: likely benign (0.0996); Very rare (popmax 0.00879%, sas); Associated with granulomatous disease, chronic, X-linked.

What condition is associated with CYBB p.Ile241Leu (c.721A>C)?

CYBB p.Ile241Leu (c.721A>C) is associated with granulomatous disease, chronic, X-linked (ClinVar).

How common is CYBB p.Ile241Leu (c.721A>C) in the general population?

CYBB p.Ile241Leu (c.721A>C) is very rare (popmax 0.00879%, sas) (gnomAD).

How is Chronic granulomatous disease inherited?

Typically Autosomal recessive, X-linked recessive (Orphanet). A genetic counselor can assess individual risk for a family.

What do computational predictors say about CYBB p.Ile241Leu (c.721A>C)?

AlphaMissense predicts likely benign (score 0.0996) — an in-silico prediction, not a clinical call.

CYBB p.Ile241Leu

c.721A>C · rs782356966 · VCV1990428

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0996 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00879%, sas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

granulomatous disease, chronic, X-linked

Computational evidence

Protein change
AlphaMissense	0.0996	likely benign
REVEL	0.265	benign-leaning
SaProt	LLR -6.59	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -2.6	GERP -2.5
Regional constraint	o/e 1.17	unconstrained · MANE · 5,249 bp · p 0.15 · regional, not allelic
Overall
CADD	0.021	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00879% South Asian · 5/56,888 alleles

Filtering AF 0.0034% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00216%

Overall 0.000457% 5/1,095,053 alleles · very rare

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: CYBB
Protein: p.Ile241Leu
Coding: c.721A>C
MANE Select: NM_000397
dbSNP: rs782356966
Type: single nucleotide variant
Location: chrX:37799001 (GRCh38)
Structure: AlphaFold pLDDT 90.29 · 6 PDB
Residue 241: an α-helix; the ferric oxidoreductase domain

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

Disease context

granulomatous disease, chronic, X-linked — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Chronic granulomatous disease (Orphanet):

Inheritance: Autosomal recessive, X-linked recessive
Onset: Adolescent, Adult, Childhood, Infancy
Prevalence: 1-9 / 1 000 000 (Worldwide)

Similar variants

CYBB c.1315-2A>G Pathogenic/Likely pathogenic ★★ same condition
CYBB c.141+1G>T Pathogenic ★★ same condition
CYBB c.252+5G>A Pathogenic ★★ same condition
CYBB c.483+1G>A Pathogenic ★★ same condition
CYBB c.483+1G>T Pathogenic ★★ same condition
CYBB c.483+3A>T Likely pathogenic ★★ same condition
CYBB p.Ala156Thr Pathogenic/Likely pathogenic ★★ ⚠ same condition
CYBB p.Ala57Glu 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/cybb-p-ile241leu (accessed [today's date]).

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