Is MTM1 p.Arg214= (c.642G>A) pathogenic?

MTM1 p.Arg214= (c.642G>A) is classified Likely benign in MTM1 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-05-12). Absent from gnomAD v4.1; Associated with X-linked myotubular myopathy.

What condition is associated with MTM1 p.Arg214= (c.642G>A)?

MTM1 p.Arg214= (c.642G>A) is associated with X-linked myotubular myopathy (ClinVar).

How common is MTM1 p.Arg214= (c.642G>A) in the general population?

MTM1 p.Arg214= (c.642G>A) is absent from gnomAD v4.1 (gnomAD).

How is X-linked centronuclear myopathy inherited?

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

MTM1 p.Arg214=

c.642G>A · VCV4738177

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

X-linked myotubular myopathy

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 5.9	GERP 1.8, phastCons 1
Overall
CADD	11.46	PHRED · no single calibrated threshold — expert panels disagree

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: MTM1
Protein: p.Arg214=
Coding: c.642G>A
MANE Select: NM_000252
Type: single nucleotide variant
Location: chrX:150641382 (GRCh38)
Structure: AlphaFold pLDDT 90.10
Residue 214: the myotubularin phosphatase domain

Full MTM1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

X-linked myotubular myopathy — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For X-linked centronuclear myopathy (Orphanet):

Inheritance: X-linked recessive
Onset: Antenatal, Neonatal
Prevalence: 1-9 / 100 000 (France)

Similar variants

MTM1 p.Arg214Gln Uncertain significance ★ ⚠ same residue
MTM1 p.Arg214Trp Uncertain significance ★ ⚠ same residue
MTM1 c.1644+1G>A Pathogenic ★★★ same condition
MTM1 p.Arg224Ter Pathogenic ★★★ same condition
MTM1 p.Arg69Cys Pathogenic ★★★ same condition
MTM1 p.Gln451= Likely pathogenic ★★★ same condition
MTM1 p.Glu404Lys Pathogenic ★★★ same condition
MTM1 p.Pro205Leu 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/mtm1-p-arg214 (accessed [today's date]).

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