Is PRF1 p.Cys176= (c.528C>T) pathogenic?

PRF1 p.Cys176= (c.528C>T) is classified Benign/Likely benign in PRF1 (ClinVar, Multiple submitters, 8 submitters; last evaluated 2026-01-26). Rare (popmax 0.147%, nfe); Associated with familial hemophagocytic lymphohistiocytosis 2.

What condition is associated with PRF1 p.Cys176= (c.528C>T)?

PRF1 p.Cys176= (c.528C>T) is associated with familial hemophagocytic lymphohistiocytosis 2 (ClinVar).

How common is PRF1 p.Cys176= (c.528C>T) in the general population?

PRF1 p.Cys176= (c.528C>T) is rare (popmax 0.147%, nfe) (gnomAD).

How is Familial hemophagocytic lymphohistiocytosis inherited?

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

PRF1 p.Cys176=

c.528C>T · rs138588977 · VCV257403

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 8 submitters

gnomAD v4.1

Rare

rare (popmax 0.147%, nfe)

Conditions

familial hemophagocytic lymphohistiocytosis 2

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 0.19	GERP -3.7, phastCons 0.22
Overall
CADD	0.704	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.147% European (non-Finnish) · 1,739/1,180,022 alleles

Filtering AF 0.142% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.139%

Overall 0.126% 2,040/1,614,114 alleles · rare exomes 1,880/1,461,864 · genomes 160/152,250 · joint denominator

Ancestry group	Frequency	1 in
Amishnot grpmax-eligible	0.658%	152
Finnishnot grpmax-eligible	0.289%	346
European (non-Finnish)grpmax	0.147%	679
Remaining individualsnot grpmax-eligible	0.118%	845
Admixed American	0.0317%	3,159
African / African-American	0.0227%	4,414

Amish shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

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: PRF1
Protein: p.Cys176=
Coding: c.528C>T
MANE Select: NM_001083116
dbSNP: rs138588977
Type: single nucleotide variant
Location: chr10:70600375 (GRCh38)
Gene constraint: LOEUF 1.438 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 91.01
Residue 176: a disulfide bond; the macpf domain

Full PRF1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

familial hemophagocytic lymphohistiocytosis 2 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Familial hemophagocytic lymphohistiocytosis (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Infancy
Prevalence: 1-9 / 100 000 (Sweden)

Similar variants

PRF1 c.539+2T>A Pathogenic/Likely pathogenic ★★ same condition
PRF1 p.Arg225Trp Pathogenic ★★ ⚠ same condition
PRF1 p.Arg232Cys Pathogenic/Likely pathogenic ★★ ⚠ same condition
PRF1 p.Arg299Cys Pathogenic/Likely pathogenic ★★ same condition
PRF1 p.Arg356Trp Pathogenic/Likely pathogenic ★★ ⚠ same condition
PRF1 p.Arg361Trp Pathogenic/Likely pathogenic ★★ ⚠ same condition
PRF1 p.Arg390Ter Pathogenic ★★ same condition
PRF1 p.Arg410Pro 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/prf1-p-cys176 (accessed [today's date]).

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