2-170386229-A-G

Variant names:

• chr2-170386229-A-G
• rs1005812892
• NM_138995.5:c.1331A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_138995.5(MYO3B):​c.1331A>G​(p.Glu444Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,566 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: 𝑓 0.000046 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MYO3B NM_138995.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.32
• Publications: 0 publications found

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

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.952

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYO3B	NM_138995.5	c.1331A>G	p.Glu444Gly	missense_variant	Exon 13 of 35	ENST00000408978.9	NP_620482.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYO3B	ENST00000408978.9	c.1331A>G	p.Glu444Gly	missense_variant	Exon 13 of 35	1	NM_138995.5	ENSP00000386213.4

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152224 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000169

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461342 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 726976

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.000149 AC: 5 AN: 33446

American (AMR) AF: 0.00 AC: 0 AN: 44692

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39674

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53392

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111642

Other (OTH) AF: 0.00 AC: 0 AN: 60360

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152224 Hom.: 0 Cov.: 32 AF XY: 0.0000672 AC XY: 5 AN XY: 74368

African (AFR) AF: 0.000169 AC: 7 AN: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5200

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10628

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68052

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.0000227

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Nov 22, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1331A>G (p.E444G) alteration is located in exon 13 (coding exon 13) of the MYO3B gene. This alteration results from a A to G substitution at nucleotide position 1331, causing the glutamic acid (E) at amino acid position 444 to be replaced by a glycine (G). 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	0.43
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.56	.;D;D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.95	D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.2	H;H;.
PhyloP100		9.3
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-6.1	D;D;D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0060	D;D;D
Sift4G	Uncertain	0.0040	.;.;D
Polyphen		1.0	D;D;.
Vest4		0.79
MVP		0.99
MPC		0.46
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.85
gMVP		0.86
Mutation Taster		=37/63	disease causing

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

Other links and lift over

dbSNP: rs1005812892; hg19: chr2-171242739;