Is LYST p.Ser3240= (c.9720C>T) pathogenic?

LYST p.Ser3240= (c.9720C>T) is classified Likely benign in LYST (ClinVar, Multiple submitters, 2 submitters; last evaluated 2025-08-31). Very rare (popmax 0.00401%, afr); Associated with Chediak-Higashi syndrome.

What condition is associated with LYST p.Ser3240= (c.9720C>T)?

LYST p.Ser3240= (c.9720C>T) is associated with Chediak-Higashi syndrome (ClinVar).

How common is LYST p.Ser3240= (c.9720C>T) in the general population?

LYST p.Ser3240= (c.9720C>T) is very rare (popmax 0.00401%, afr) (gnomAD).

How is Chédiak-Higashi syndrome inherited?

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

LYST p.Ser3240=

c.9720C>T · rs773882115 · VCV727224

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 0.00401%, afr)

Conditions

Chediak-Higashi syndrome

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 -5	GERP -5.9
Overall
CADD	7.506	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00401% African / African-American · 3/74,884 alleles

Filtering AF 0.00111% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0009%

Overall 0.00155% 25/1,613,620 alleles · very rare exomes 24/1,461,500 · genomes 1/152,120 · joint denominator

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.00401%	24,961
European (non-Finnish)	0.0017%	58,986
Remaining individualsnot grpmax-eligible	0.0016%	62,472
South Asian	0.0011%	91,070

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: LYST
Protein: p.Ser3240=
Coding: c.9720C>T
MANE Select: NM_000081
dbSNP: rs773882115
Type: single nucleotide variant
Location: chr1:235715265 (GRCh38)
Gene constraint: LOEUF 0.505 · pLI <0.01 (gnomAD)
Residue 3240: a UniProt-annotated variant site (in chs); the beach domain

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

Disease context

Chediak-Higashi syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Chédiak-Higashi syndrome (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood

Similar variants

LYST c.192+1G>A Pathogenic/Likely pathogenic ★★ same condition
LYST c.4862+2T>A Likely pathogenic ★★ same condition
LYST c.4863-1G>C Likely pathogenic ★★ same condition
LYST c.6882-1G>T Likely pathogenic ★★ same condition
LYST c.8358+2T>C Pathogenic/Likely pathogenic ★★ same condition
LYST c.8358+2T>G Likely pathogenic ★★ same condition
LYST c.8802-2A>G Pathogenic/Likely pathogenic ★★ same condition
LYST c.9784+1G>T 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/lyst-p-ser3240 (accessed [today's date]).

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