2-170387223-A-G

Position:

• chr2-170387223-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_138995.5(MYO3B):​c.1492A>G​(p.Met498Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,794 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MYO3B NM_138995.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.29

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-AS1 (HGNC:40713): (MYO3B antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYO3B	NM_138995.5	c.1492A>G	p.Met498Val	missense_variant	14/35	ENST00000408978.9	NP_620482.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYO3B	ENST00000408978.9	c.1492A>G	p.Met498Val	missense_variant	14/35	1	NM_138995.5	ENSP00000386213	P1
MYO3B-AS1	ENST00000625968.2	n.54-1338T>C		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461794 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727202

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 29, 2024

The c.1492A>G (p.M498V) alteration is located in exon 14 (coding exon 14) of the MYO3B gene. This alteration results from a A to G substitution at nucleotide position 1492, causing the methionine (M) at amino acid position 498 to be replaced by a valine (V). 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	Uncertain	0.35
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Uncertain	23
DANN	Uncertain	0.98
DEOGEN2	Benign	0.20	.;T;T
Eigen	Uncertain	0.23
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D;D;D
M_CAP	Benign	0.027	D
MetaRNN	Uncertain	0.62	D;D;D
MetaSVM	Benign	-0.64	T
MutationAssessor	Benign	-0.080	N;N;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.75	T
PROVEAN	Uncertain	-2.4	N;N;N
REVEL	Uncertain	0.54
Sift	Benign	0.058	T;T;T
Sift4G	Benign	0.29	.;.;T
Polyphen		0.18	B;P;.
Vest4		0.94
MutPred		0.51		Gain of ubiquitination at K494 (P = 0.1128);Gain of ubiquitination at K494 (P = 0.1128);.;
MVP		0.72
MPC		0.14
ClinPred		0.87	D
GERP RS		5.6
Varity_R		0.50
gMVP		0.65

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

Other links and lift over

dbSNP: rs1211166152; hg19: chr2-171243733;