rs797045715

Variant names:

• chrX-150659749-CAAAACAGGT-C
• rs797045715
• NM_000252.3:c.1349_1353+4delAACAGGTAA

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.1349_1353+4delAACAGGTAA​(p.Lys450ProfsTer152) variant causes a frameshift, splice donor, splice region, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 22)
• Consequence: MTM1 NM_000252.3 frameshift, splice_donor, splice_region, intron
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 9.90
• Publications: 0 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: G2P, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen, Myriad Women’s Health, Orphanet

ACMG classification

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-150659749-CAAAACAGGT-C is Pathogenic according to our data. Variant chrX-150659749-CAAAACAGGT-C is described in ClinVar as Pathogenic. ClinVar VariationId is 211530.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MTM1	NM_000252.3	c.1349_1353+4delAACAGGTAA	p.Lys450ProfsTer152	frameshift_variant, splice_donor_variant, splice_region_variant, intron_variant	Exon 12 of 15	ENST00000370396.7	NP_000243.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MTM1	ENST00000370396.7	c.1347_1353+2delAAAACAGGT	p.Lys450ProfsTer152	frameshift_variant, splice_donor_variant, splice_region_variant, intron_variant	Exon 12 of 15	1	NM_000252.3	ENSP00000359423.3

Frequencies

GnomAD3 genomes Cov.: 22

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 22

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Severe X-linked myotubular myopathy Pathogenic:2

Mar 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 211530). This variant has been observed in individual(s) with myopathy (Invitae). This variant is not present in population databases (gnomAD no frequency). This variant results in the deletion of part of exon 12 (c.1349_1353+4del) of the MTM1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in MTM1 are known to be pathogenic (PMID: 9305655, 10063835). -

Feb 08, 2013

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.9
Mutation Taster		=1/199	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs797045715; hg19: chrX-149828222;