Genetic Variant MBNL2:p.Thr146Met (chr13-97343113-C-T) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_001382683.1(MBNL2):c.437C>T(p.Thr146Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000229 in 1,613,826 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T146R) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

MBNL2
NM_001382683.1 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.50

Variant links:

Genes affected

MBNL2 (HGNC:16746): (muscleblind like splicing regulator 2) This gene is a member of the muscleblind protein family which was initially described in Drosophila melanogaster. This gene encodes a C3H-type zinc finger protein that modulates alternative splicing of pre-mRNAs. Muscleblind proteins bind specifically to expanded dsCUG RNA but not to normal size CUG repeats and may thereby play a role in the pathophysiology of myotonic dystrophy. Several alternatively spliced transcript variants have been described but the full-length natures of only some have been determined. [provided by RefSeq, Mar 2012]

MBNL2 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BS2

High AC in GnomAd4 at 6 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MBNL2	NM_001382683.1 link	c.437C>T	p.Thr146Met	missense_variant	Exon 4 of 9	ENST00000679496.1	NP_001369612.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MBNL2	ENST00000679496.1 link	c.437C>T	p.Thr146Met	missense_variant	Exon 4 of 9		NM_001382683.1	ENSP00000505596.1		A0A7P0T9I3

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152188

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000621

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000278

AC:

AN:

251474

Hom.:

AF XY:

0.0000294

AC XY:

AN XY:

135916

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000196

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000212

AC:

AN:

1461638

Hom.:

Cov.:

AF XY:

0.0000261

AC XY:

AN XY:

727144

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000151

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000153

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152188

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000621

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jun 17, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.437C>T (p.T146M) alteration is located in exon 4 (coding exon 3) of the MBNL2 gene. This alteration results from a C to T substitution at nucleotide position 437, causing the threonine (T) at amino acid position 146 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.17

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Benign

-0.26

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.40

.;T;.;.

Eigen

Pathogenic

0.69

Eigen_PC

Pathogenic

0.73

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.98

D;D;.;D

M_CAP

Benign

0.018

MetaRNN

Uncertain

0.51

D;D;D;D

MetaSVM

Benign

-0.90

MutationAssessor

Uncertain

2.1

M;M;M;M

PrimateAI

Uncertain

0.68

PROVEAN

Benign

-1.9

N;N;N;N

REVEL

Benign

0.22

Sift

Benign

0.16

T;T;T;T

Sift4G

Uncertain

0.024

D;D;D;D

Polyphen

0.99, 1.0

.;D;.;D

Vest4

0.75

MVP

0.093

MPC

1.9

ClinPred

0.67

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.11

gMVP

0.81

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over