Is UNC13D p.Ser420= (c.1260T>C) pathogenic?

UNC13D p.Ser420= (c.1260T>C) is classified Likely benign in UNC13D (ClinVar, Single submitter, 1 submitter; last evaluated 2024-02-08). Very rare (popmax 0.000424%, nfe); Associated with familial hemophagocytic lymphohistiocytosis 3.

What condition is associated with UNC13D p.Ser420= (c.1260T>C)?

UNC13D p.Ser420= (c.1260T>C) is associated with familial hemophagocytic lymphohistiocytosis 3 (ClinVar).

How common is UNC13D p.Ser420= (c.1260T>C) in the general population?

UNC13D p.Ser420= (c.1260T>C) is very rare (popmax 0.000424%, nfe) (gnomAD).

How is Familial hemophagocytic lymphohistiocytosis inherited?

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

UNC13D p.Ser420=

c.1260T>C · VCV3715139

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.000424%, nfe)

Conditions

familial hemophagocytic lymphohistiocytosis 3

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 -2.9
Overall
CADD	2.545	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000424% European (non-Finnish) · 5/1,180,004 alleles

Filtering AF 0.000124% ClinGen BA1/BS1 input FAF95, joint · FAF99 9e-05%

Overall 0.00031% 5/1,613,750 alleles · very rare exomes 5/1,461,452 · genomes 0/152,298 · 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: UNC13D
Protein: p.Ser420=
Coding: c.1260T>C
MANE Select: NM_199242
Type: single nucleotide variant
Location: chr17:75836610 (GRCh38)
Gene constraint: LOEUF 0.923 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 85.04 · 1 PDB
Residue 420: the 'interaction with rab27a' region

Full UNC13D gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

familial hemophagocytic lymphohistiocytosis 3 — 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

UNC13D p.Ser420fs Pathogenic ★ same residue
UNC13D c.1055+1G>A Pathogenic/Likely pathogenic ★★ same condition
UNC13D c.118-307G>A Pathogenic ★★ same condition
UNC13D c.118-308C>T Pathogenic/Likely pathogenic ★★ same condition
UNC13D c.1389+1G>A Pathogenic ★★ same condition
UNC13D c.1596+1G>C Pathogenic ★★ same condition
UNC13D c.1727+1G>A Pathogenic/Likely pathogenic ★★ same condition
UNC13D c.1848+1G>A 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/unc13d-p-ser420 (accessed [today's date]).

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