Is MTFMT p.Cys8fs (c.13_23dup) pathogenic?

MTFMT p.Cys8fs (c.1323dup) is classified Pathogenic in MTFMT (ClinVar, Single submitter, 1 submitter; last evaluated 2020-09-09). No gnomAD frequency available for this variant.

How common is MTFMT p.Cys8fs (c.13_23dup) in the general population?

MTFMT p.Cys8fs (c.13_23dup) is no gnomAD frequency available for this variant (gnomAD).

MTFMT p.Cys8fs

c.13_23dup · rs2140493897 · VCV1323300

Pathogenic Single submitter

Classification

Pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

frameshift

predicted LoF

gnomAD v4.1

Not reported

no gnomAD frequency available for this variant

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	frameshift	predicted loss-of-function
NMD	predicted	premature termination codon in exon 1 of 9
Splicing
SpliceAI	—	not assessed · substitutions only
Constraint at this position
Conservation	phyloP 0.85	GERP -1, phastCons 0.54

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

dbSNP / gnomAD

No gnomAD frequency available for this variant. This is missing data, not an absence: the variant may or may not be present in gnomAD. Rarity (ACMG PM2) and BA1/BS1 cannot be assessed for it.

Variant & gene context

Gene: MTFMT
Protein: p.Cys8fs
Coding: c.13_23dup
MANE Select: NM_139242
dbSNP: rs2140493897
Type: Duplication
Location: chr15:65029590 (GRCh38)
Gene constraint: LOEUF 1.304 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 86.08

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

Similar variants

MTFMT p.Cys8Ser Uncertain significance ★ ⚠ same residue
MTFMT p.Thr381fs Uncertain significance ★★ same type
MTFMT p.Tyr240Ter Pathogenic ★ same type
MTFMT p.Arg7_Cys8insTerArg Uncertain significance ★ same type
MTFMT c.210-175dup Likely benign ★ same type
MTFMT c.542+174_542+181dup Likely benign ★ same type
MTFMT c.646-18_646-17dup Likely benign ★ same type
MTFMT c.646-18dup Benign ★ same type

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/mtfmt-p-cys8fs (accessed [today's date]).

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