Is ABCC8 p.Asn331= (c.993C>T) pathogenic?

ABCC8 p.Asn331= (c.993C>T) is classified Conflicting classifications of pathogenicity in ABCC8 (ClinVar, Conflicting submitters, 2 submitters; last evaluated 2022-09-09). Very rare (popmax 0.00161%, nfe); Associated with transient neonatal diabetes mellitus.

What condition is associated with ABCC8 p.Asn331= (c.993C>T)?

ABCC8 p.Asn331= (c.993C>T) is associated with transient neonatal diabetes mellitus, maturity-onset diabetes of the young (ClinVar).

How common is ABCC8 p.Asn331= (c.993C>T) in the general population?

ABCC8 p.Asn331= (c.993C>T) is very rare (popmax 0.00161%, nfe) (gnomAD).

ABCC8 p.Asn331=

c.993C>T · rs752188418 · VCV799128

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 0.00161%, nfe)

Conditions

transient neonatal diabetes mellitus

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	<0.2	no splice effect predicted · four deltas, not one · how we know
Constraint at this position
Conservation	phyloP 0.98	GERP -2.9, phastCons 1
Overall
CADD	9.835	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00161% European (non-Finnish) · 19/1,180,036 alleles

Filtering AF 0.00103% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00083%

Overall 0.0013% 21/1,614,026 alleles · very rare exomes 20/1,461,798 · genomes 1/152,228 · joint denominator

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.00161%	62,107
Remaining individualsnot grpmax-eligible	0.0016%	62,488
South Asian	0.0011%	91,088

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.Asn331=
Coding: c.993C>T
MANE Select: NM_000352
dbSNP: rs752188418
Type: single nucleotide variant
Location: chr11:17460506 (GRCh38)
Gene constraint: LOEUF 0.829 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 82.56 · 8 PDB
Residue 331: the abc transmembrane type-1 1 domain

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

Disease context

transient neonatal diabetes mellitus — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: maturity-onset diabetes of the young

Similar variants

ABCC8 c.2116+2T>C Pathogenic/Likely pathogenic ★★ same condition
ABCC8 c.3868-1G>A Pathogenic/Likely pathogenic ★★ same condition
ABCC8 c.3989-9G>A Pathogenic ★★ same condition
ABCC8 c.4308-2A>G Pathogenic/Likely pathogenic ★★ same condition
ABCC8 p.Arg1379His Pathogenic/Likely pathogenic ★★ same condition
ABCC8 p.Arg1538Gln Pathogenic/Likely pathogenic ★★ ⚠ same condition
ABCC8 p.Gly228Asp Pathogenic/Likely pathogenic ★★ same condition
ABCC8 p.Gly716Ser 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/abcc8-p-asn331 (accessed [today's date]).

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