chrX-150641404-C-T

Variant names:

• chrX-150641404-C-T
• rs587783847
• NM_000252.3:c.664C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000252.3(MTM1):​c.664C>T​(p.Arg222*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R222R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay. The gene MTM1 is included in the ClinGen Criteria Specification Registry.

• Frequency: Genomes: not found (cov: 22)
• Consequence: MTM1 NM_000252.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 1.67
• Publications: 4 publications found

Genes affected

MTM1 (HGNC:7448): (myotubularin 1) This gene encodes a dual-specificity phosphatase that acts on both phosphotyrosine and phosphoserine. It is required for muscle cell differentiation and mutations in this gene have been identified as being responsible for X-linked myotubular myopathy. [provided by RefSeq, Jul 2008]

MTM1 Gene-Disease associations (from GenCC):

• X-linked myotubular myopathy

  Inheritance: XL Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, G2P, Myriad Women’s Health, Ambry Genetics

ACMG classification

Specifications for MTM1 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-150641404-C-T is Pathogenic according to our data. Variant chrX-150641404-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 158994.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000252.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MTM1	NM_000252.3	MANE Select	c.664C>T	p.Arg222*	stop_gained	Exon 8 of 15	NP_000243.1	Q13496-1
	MTM1	NM_001376908.1		c.664C>T	p.Arg222*	stop_gained	Exon 8 of 15	NP_001363837.1	Q13496-1
	MTM1	NM_001376906.1		c.664C>T	p.Arg222*	stop_gained	Exon 8 of 15	NP_001363835.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MTM1	ENST00000370396.7	TSL:1 MANE Select	c.664C>T	p.Arg222*	stop_gained	Exon 8 of 15	ENSP00000359423.3	Q13496-1
	MTM1	ENST00000688403.1		c.-81C>T		5_prime_UTR_premature_start_codon_gain	Exon 3 of 10	ENSP00000508944.1	A0A8I5KQR6
	MTM1	ENST00000690282.1		c.-81C>T		5_prime_UTR_premature_start_codon_gain	Exon 3 of 10	ENSP00000509809.1	A0A8I5KQR6

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 22

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
4	-	-	Severe X-linked myotubular myopathy (4)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	36
DANN	Uncertain	1.0
FATHMM_MKL	Uncertain	0.91	D
PhyloP100		1.7
Vest4		0.93
GERP RS		1.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs587783847; hg19: chrX-149809877; COSMIC: COSV60334206; COSMIC: COSV60334206;