Genetic Variant MYO3B:p.Ser113Leu (chr2-170214395-C-T) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_138995.5(MYO3B):c.338C>T(p.Ser113Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,820 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

MYO3B
NM_138995.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.49

Variant links:

Genes affected

MYO3B (HGNC:15576): (myosin IIIB) This gene encodes one of the class III myosins. Myosins are ATPases, activated by actin, that move along actin filaments in the cell. This class of myosins are characterized by an amino-terminal kinase domain and shown to be present in photoreceptors. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Mar 2014]

MYO3B links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.859

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYO3B	NM_138995.5 link	c.338C>T	p.Ser113Leu	missense_variant	Exon 4 of 35	ENST00000408978.9	NP_620482.3	Q8WXR4-1B7ZM71

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYO3B	ENST00000408978.9 link	c.338C>T	p.Ser113Leu	missense_variant	Exon 4 of 35	1	NM_138995.5	ENSP00000386213.4		Q8WXR4-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000241

AC:

AN:

249430

Hom.:

AF XY:

0.0000222

AC XY:

AN XY:

135306

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000174

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000616

AC:

AN:

1461820

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727208

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.000134

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000248

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Mar 05, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.338C>T (p.S113L) alteration is located in exon 4 (coding exon 4) of the MYO3B gene. This alteration results from a C to T substitution at nucleotide position 338, causing the serine (S) at amino acid position 113 to be replaced by a leucine (L). 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

Pathogenic

0.81

BayesDel_addAF

Benign

-0.13

BayesDel_noAF

Benign

-0.15

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.022

.;T;T

Eigen

Pathogenic

0.83

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Uncertain

0.82

LIST_S2

Pathogenic

0.99

D;D;D

M_CAP

Benign

0.075

MetaRNN

Pathogenic

0.86

D;D;D

MetaSVM

Benign

-0.99

MutationAssessor

Benign

2.0

M;M;.

PrimateAI

Uncertain

0.58

PROVEAN

Pathogenic

-5.5

D;D;D

REVEL

Uncertain

0.47

Sift

Uncertain

0.0010

D;D;D

Sift4G

Uncertain

0.0020

.;.;D

Polyphen

1.0

D;D;.

Vest4

0.93

MutPred

0.66

Loss of catalytic residue at S113 (P = 0.2106);Loss of catalytic residue at S113 (P = 0.2106);.;

MVP

0.72

MPC

0.41

ClinPred

0.99

GERP RS

5.5

Varity_R

0.94

gMVP

0.69

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