Is ABCC8 p.Ile255= (c.765C>T) pathogenic?

ABCC8 p.Ile255= (c.765C>T) is classified Likely benign in ABCC8 (ClinVar, Multiple submitters, 3 submitters; last evaluated 2024-02-25). Very rare (popmax 0.00801%, afr); Associated with hyperinsulinemic hypoglycemia, familial, 1.

What condition is associated with ABCC8 p.Ile255= (c.765C>T)?

ABCC8 p.Ile255= (c.765C>T) is associated with hyperinsulinemic hypoglycemia, familial, 1, type 2 diabetes mellitus, hypoglycemia, leucine-induced (ClinVar).

How common is ABCC8 p.Ile255= (c.765C>T) in the general population?

ABCC8 p.Ile255= (c.765C>T) is very rare (popmax 0.00801%, afr) (gnomAD).

ABCC8 p.Ile255=

c.765C>T · rs753335564 · VCV806626

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

gnomAD v4.1

Rare

very rare (popmax 0.00801%, afr)

Conditions

hyperinsulinemic hypoglycemia, familial, 1

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 -7.1	GERP -4.9
Overall
CADD	5.268	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00801% African / African-American · 6/74,950 alleles

Filtering AF 0.00511% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00468%

Overall 0.0052% 84/1,614,138 alleles · very rare

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.00801%	12,492
European (non-Finnish)	0.00627%	15,947
Admixed American	0.00167%	60,012
Remaining individualsnot grpmax-eligible	0.0016%	62,490
Finnishnot grpmax-eligible	0.00156%	64,050
South Asian	0.0011%	91,094

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: ABCC8
Protein: p.Ile255=
Coding: c.765C>T
MANE Select: NM_000352
dbSNP: rs753335564
Type: single nucleotide variant
Location: chr11:17461640 (GRCh38)
Gene constraint: LOEUF 0.829 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 82.56 · 8 PDB

Full ABCC8 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

hyperinsulinemic hypoglycemia, familial, 1 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: type 2 diabetes mellitus hypoglycemia, leucine-induced diabetes mellitus, transient neonatal, 2 diabetes mellitus, permanent neonatal 3

Similar variants

ABCC8 p.Ile255Val Uncertain significance ★ ⚠ same residue
ABCC8 p.Ile255Met Uncertain significance ★ ⚠ same residue
ABCC8 c.1176+2T>C Pathogenic/Likely pathogenic ★★ same condition
ABCC8 c.1333-1013A>G Pathogenic/Likely pathogenic ★★ same condition
ABCC8 c.148+1G>A Pathogenic/Likely pathogenic ★★ same condition
ABCC8 c.148+2T>G Likely pathogenic ★★ same condition
ABCC8 c.1630+1G>A Pathogenic/Likely pathogenic ★★ same condition
ABCC8 c.1630+1G>T 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/abcc8-p-ile255 (accessed [today's date]).

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