Is NPHP1 p.Ile326Ser (c.977T>G) pathogenic?

NPHP1 p.Ile326Ser (c.977T>G) is classified Uncertain significance in NPHP1 (ClinVar, Single submitter, 1 submitter; last evaluated 2024-06-17). AlphaMissense: ambiguous (0.3836); Very rare (popmax 0.00017%, nfe); Associated with nephronophthisis 1.

What condition is associated with NPHP1 p.Ile326Ser (c.977T>G)?

NPHP1 p.Ile326Ser (c.977T>G) is associated with nephronophthisis 1, Senior-Loken syndrome 1, Joubert syndrome with renal defect (ClinVar).

How common is NPHP1 p.Ile326Ser (c.977T>G) in the general population?

NPHP1 p.Ile326Ser (c.977T>G) is very rare (popmax 0.00017%, nfe) (gnomAD).

What do computational predictors say about NPHP1 p.Ile326Ser (c.977T>G)?

AlphaMissense predicts ambiguous (score 0.3836) — an in-silico prediction, not a clinical call.

NPHP1 p.Ile326Ser

c.977T>G · VCV3584255

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

ambiguous

0.3836 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00017%, nfe)

Conditions

nephronophthisis 1

Computational evidence

Protein change
AlphaMissense	0.3836	ambiguous
REVEL	0.478	indeterminate
SaProt	LLR -8.57	tolerated
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 7.9	GERP 0.43, phastCons 0.97
Regional constraint	o/e 0.96	unconstrained · MANE · 81 kb · p 0.26 · regional, not allelic
Overall
CADD	22.7	PHRED · no single calibrated threshold — expert panels disagree

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

⚠ Isoform check: AlphaMissense numbered on a different transcript (AM I381S vs ClinVar I326S) — verify the residue.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00017% European (non-Finnish) · 2/1,177,734 alleles

Filtering AF 2.8e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 1.1e-05%

Overall 0.000124% 2/1,611,548 alleles · very rare exomes 2/1,459,256 · genomes 0/152,292 · joint denominator

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: NPHP1
Protein: p.Ile326Ser
Coding: c.977T>G
MANE Select: NM_001128178
Type: single nucleotide variant
Location: chr2:110160233 (GRCh38)
Gene constraint: LOEUF 0.92 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 76.22 · 2 PDB

Full NPHP1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

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

Also linked: Senior-Loken syndrome 1 Joubert syndrome with renal defect

Similar variants

NPHP1 p.Ile326Val Uncertain significance ★ ⚠ same residue
NPHP1 p.Ile326Met Uncertain significance ⚠ same residue
NPHP1 c.1083+1G>A Likely pathogenic ★★ same condition
NPHP1 c.1270-1G>A Pathogenic ★★ same condition
NPHP1 c.1270-2A>G Pathogenic/Likely pathogenic ★★ same condition
NPHP1 c.143+1G>C Likely pathogenic ★★ same condition
NPHP1 c.144-1G>A Pathogenic/Likely pathogenic ★★ same condition
NPHP1 c.1716+1G>T 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/nphp1-p-ile326ser (accessed [today's date]).

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