Is NPHP4 p.Thr556= (c.1668C>T) pathogenic?

NPHP4 p.Thr556= (c.1668C>T) is classified Conflicting classifications of pathogenicity in NPHP4 (ClinVar, Conflicting submitters, 3 submitters; last evaluated 2026-01-29). Ultra-rare (popmax 0.01%, nfe); Associated with nephronophthisis.

What condition is associated with NPHP4 p.Thr556= (c.1668C>T)?

NPHP4 p.Thr556= (c.1668C>T) is associated with nephronophthisis, nephronophthisis 4, Senior-Loken syndrome 4 (ClinVar).

How common is NPHP4 p.Thr556= (c.1668C>T) in the general population?

NPHP4 p.Thr556= (c.1668C>T) is ultra-rare (popmax 0.01%, nfe) (gnomAD).

How is Nephronophthisis inherited?

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

NPHP4 p.Thr556=

c.1668C>T · rs753733095 · VCV297817

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 3 submitters

gnomAD v4.1

Rare

ultra-rare (popmax 0.01%, nfe)

Conditions

nephronophthisis

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 -2.2	GERP -4.3
Overall
CADD	0.23	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.01% European (non-Finnish) · 118/1,179,684 alleles

Filtering AF 0.00851% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00796%

Overall 0.00762% 123/1,613,448 alleles · ultra-rare exomes 110/1,461,230 · genomes 13/152,218 · joint denominator

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.01%	9,997
Remaining individualsnot grpmax-eligible	0.0032%	31,224
African / African-American	0.00267%	37,458
Admixed American	0.00167%	59,938

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.Thr556=
Coding: c.1668C>T
MANE Select: NM_015102
dbSNP: rs753733095
Type: single nucleotide variant
Location: chr1:5905727 (GRCh38)
Gene constraint: LOEUF 1.183 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 72.44

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

Also linked: nephronophthisis 4 Senior-Loken syndrome 4

For Nephronophthisis (Orphanet):

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

Similar variants

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.517+1G>A 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-thr556 (accessed [today's date]).

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