Is NPHP4 p.Arg1326His (c.3977G>A) pathogenic?

NPHP4 p.Arg1326His (c.3977G>A) is classified Uncertain significance in NPHP4 (ClinVar, Single submitter, 2 submitters; last evaluated 2020-01-27). AlphaMissense: likely benign (0.1049); Very rare (popmax 0.00553%, sas); Associated with nephronophthisis.

What condition is associated with NPHP4 p.Arg1326His (c.3977G>A)?

NPHP4 p.Arg1326His (c.3977G>A) is associated with nephronophthisis (ClinVar).

How common is NPHP4 p.Arg1326His (c.3977G>A) in the general population?

NPHP4 p.Arg1326His (c.3977G>A) is very rare (popmax 0.00553%, sas) (gnomAD).

How is Nephronophthisis inherited?

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

What do computational predictors say about NPHP4 p.Arg1326His (c.3977G>A)?

AlphaMissense predicts likely benign (score 0.1049) — an in-silico prediction, not a clinical call.

NPHP4 p.Arg1326His

c.3977G>A · rs191062831 · VCV1025374

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 2 submitters

AlphaMissense

likely benign

0.1049 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00553%, sas)

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL indeterminate

Conditions

nephronophthisis

Computational evidence

Protein change
AlphaMissense	0.1049	likely benign
REVEL	0.526	indeterminate
SaProt	LLR -7.56	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL is indeterminate.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 3.1	GERP 0.49, phastCons 1
Regional constraint	o/e 1.02	unconstrained · MANE · 123 kb · p 0.49 · regional, not allelic
Overall
CADD	25.4	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

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

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00553% South Asian · 5/90,444 alleles

Filtering AF 0.00211% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00137%

Overall 0.000933% 15/1,607,140 alleles · very rare exomes 13/1,454,900 · genomes 2/152,240 · joint denominator

Ancestry group	Frequency	1 in
South Asiangrpmax	0.00553%	18,089
African / African-American	0.00534%	18,724
East Asian	0.00223%	44,744
European (non-Finnish)	0.000425%	235,322

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: NPHP4
Protein: p.Arg1326His
Coding: c.3977G>A
MANE Select: NM_015102
dbSNP: rs191062831
Type: single nucleotide variant
Location: chr1:5864357 (GRCh38)
Gene constraint: LOEUF 1.183 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 72.44
Residue 1326: the 'sufficient for basal bodies localization' region

Full NPHP4 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

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

For Nephronophthisis (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Adult, Antenatal, Childhood, Infancy, Neonatal
Prevalence: 1-9 / 100 000 (Finland)

Similar variants

NPHP4 p.Arg1326Cys Uncertain significance ★★ ⚠ same residue
NPHP4 c.2304+1G>A Pathogenic ★★ same condition
NPHP4 c.2611+1G>A Pathogenic/Likely pathogenic ★★ same condition
NPHP4 c.2611+1G>C Pathogenic ★★ same condition
NPHP4 c.3644+1G>A Pathogenic/Likely pathogenic ★★ same condition
NPHP4 c.3644+1G>T Pathogenic/Likely pathogenic ★★ same condition
NPHP4 c.518-2A>G Likely pathogenic ★★ same condition
NPHP4 c.992+2T>C 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/nphp4-p-arg1326his (accessed [today's date]).

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