Is CLN8 p.Cys103Phe (c.308G>T) pathogenic?

CLN8 p.Cys103Phe (c.308G>T) is classified Uncertain significance in CLN8 (ClinVar, No assertion criteria, 1 submitter; last evaluated 2025-04-18). AlphaMissense: likely pathogenic (0.891); Absent from gnomAD v4.1; Associated with neuronal ceroid lipofuscinosis 8.

What condition is associated with CLN8 p.Cys103Phe (c.308G>T)?

CLN8 p.Cys103Phe (c.308G>T) is associated with neuronal ceroid lipofuscinosis 8 (ClinVar).

How common is CLN8 p.Cys103Phe (c.308G>T) in the general population?

CLN8 p.Cys103Phe (c.308G>T) is absent from gnomAD v4.1 (gnomAD).

How is CLN8 disease inherited?

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

What do computational predictors say about CLN8 p.Cys103Phe (c.308G>T)?

AlphaMissense predicts likely pathogenic (score 0.891) — an in-silico prediction, not a clinical call.

CLN8 p.Cys103Phe

c.308G>T · VCV4064844

Uncertain significance No assertion criteria

Classification

Uncertain significance

ClinVar

Review

No assertion criteria ☆☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.891 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

1/2 damaging

AlphaMissense, SaProt · REVEL no call

Conditions

neuronal ceroid lipofuscinosis 8

Computational evidence

Protein change
AlphaMissense	0.891	likely pathogenic
REVEL	0.588	indeterminate
SaProt	LLR -5.82	tolerated
⇒ AlphaMissense calls this damaging; SaProt does not; REVEL makes no call.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 6.8	GERP 0.82, phastCons 1
Regional constraint	o/e 1.14	unconstrained · MANE · 9,509 bp · p 0.0075 · regional, not allelic
Overall
CADD	23.3	PHRED · no single calibrated threshold — expert panels disagree

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

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: CLN8
Protein: p.Cys103Phe
Coding: c.308G>T
MANE Select: NM_018941
Type: single nucleotide variant
Location: chr8:1771362 (GRCh38)
Gene constraint: LOEUF 1.183 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 90.47 · 3 PDB
Residue 103: the tlc domain

Full CLN8 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

neuronal ceroid lipofuscinosis 8 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For CLN8 disease (Orphanet):

Inheritance: Autosomal recessive
Onset: Infancy

Similar variants

CLN8 p.Arg204Cys Pathogenic/Likely pathogenic ★★ same condition
CLN8 p.Arg204His Likely pathogenic ★★ same condition
CLN8 p.Arg24Gly Pathogenic ★★ same condition
CLN8 p.Arg70Cys Pathogenic/Likely pathogenic ★★ same condition
CLN8 p.Arg70His Pathogenic/Likely pathogenic ★★ same condition
CLN8 p.Gln255Ter Pathogenic ★★ same condition
CLN8 p.Gln99Ter Pathogenic/Likely pathogenic ★★ same condition
CLN8 p.Glu167Ter 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/cln8-p-cys103phe (accessed [today's date]).

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