X-150659700-G-A

Position:

• chrX-150659700-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PS1_Moderate PM2 PP3

The NM_000252.3(MTM1):​c.1297G>A​(p.Asp433Asn) variant causes a missense change involving the alteration of a 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 Uncertain significance (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin UniProt.

• Frequency: Genomes: not found (cov: 23)
• Consequence: MTM1 NM_000252.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 9.94

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PS1: Transcript NM_000252.3 (MTM1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.822

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MTM1	NM_000252.3	c.1297G>A	p.Asp433Asn	missense_variant	12/15	ENST00000370396.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MTM1	ENST00000370396.7	c.1297G>A	p.Asp433Asn	missense_variant	12/15	1	NM_000252.3	P1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	May 16, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	May 23, 2017	The p.Asp433Asn variant in MTM1 has been reported in 1 male with X-linked recessive myotubular myopathy, who carried a second variant 2 amino acids upstream on the same allele (p.Asp431Asn; Laporte 1997). Please note, it is unclear if these two variants occurred independently or as a single event (p.Asp431_Asp433delinsAsnAlaAsn). Both variants were absent from large population studies. Computational prediction tools and conservation analyses suggest that the p.Asp433Asn variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, the clinical significance of the p.Asp433Asn variant is uncertain. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

May 22, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.59
BayesDel_addAF	Benign	0.011	T
BayesDel_noAF	Benign	-0.22
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.82	D
MetaSVM	Uncertain	0.62	D
MutationAssessor	Uncertain	2.4	M
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.80	T
PROVEAN	Uncertain	-3.9	D
REVEL	Uncertain	0.61
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0040	D
Polyphen		0.98	D
Vest4		0.84
MutPred		0.33		Loss of catalytic residue at D433 (P = 0.0447);
MVP		0.95
MPC		1.6
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.76
gMVP		0.78

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.37		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.37		Position offset: -36

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

Publications

LitVar

Other links and lift over

dbSNP: rs886044783; hg19: chrX-149828173;