Is MRTFA p.Ala108= (c.324C>T) pathogenic?

MRTFA p.Ala108= (c.324C>T) is classified Benign/Likely benign in MRTFA (ClinVar, Multiple submitters, 2 submitters; last evaluated 2025-12-31). Very rare (popmax 0.00988%, sas).

How common is MRTFA p.Ala108= (c.324C>T) in the general population?

MRTFA p.Ala108= (c.324C>T) is very rare (popmax 0.00988%, sas) (gnomAD).

MRTFA p.Ala108=

c.324C>T · rs202073037 · VCV1683163

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 0.00988%, sas)

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 4	GERP -4.8, phastCons 1
Overall
CADD	13.8	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00988% South Asian · 9/91,078 alleles

Filtering AF 0.00514% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00375%

Overall 0.0172% 277/1,614,118 alleles · very rare exomes 232/1,461,858 · genomes 45/152,260 · joint denominator

Ancestry group	Frequency	1 in
Finnishnot grpmax-eligible	0.364%	275
South Asiangrpmax	0.00988%	10,120
Remaining individualsnot grpmax-eligible	0.0096%	10,418
East Asian	0.00668%	14,961
Admixed American	0.00333%	30,006
European (non-Finnish)	0.00195%	51,305
African / African-American	0.00133%	75,002

Finnish 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: MRTFA
Protein: p.Ala108=
Coding: c.324C>T
MANE Select: NM_020831
dbSNP: rs202073037
Type: single nucleotide variant
Location: chr22:40435538 (GRCh38)
Gene constraint: LOEUF 0.389 · pLI 1.00 (gnomAD)
Structure: AlphaFold pLDDT 56.59 · 2 PDB
Residue 108: the 'mediates interaction with scai and actb' region

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

Similar variants

MRTFA p.Ala352Thr Uncertain significance ★★ ⚠ same type
MRTFA p.Ala360Thr Uncertain significance ★★ ⚠ same type
MRTFA p.Ala429Ser Uncertain significance ★★ ⚠ same type
MRTFA p.Ala479Gly Uncertain significance ★★ ⚠ same type
MRTFA p.Ala479Val Uncertain significance ★★ ⚠ same type
MRTFA p.Ala534Thr Uncertain significance ★★ ⚠ same type
MRTFA p.Ala537Val Uncertain significance ★★ ⚠ same type
MRTFA p.Ala616Val Uncertain significance ★★ ⚠ 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/mrtfa-p-ala108 (accessed [today's date]).

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