2-170383722-T-C

Variant names:

• chr2-170383722-T-C
• rs1260527308
• NM_138995.5:c.1198T>C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_138995.5(MYO3B):​c.1198T>C​(p.Tyr400His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000198 in 1,461,106 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: 32)
  • Exomes 𝑓: 0.000020 (0 hom.)
• Consequence: MYO3B NM_138995.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.99

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.977

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYO3B	NM_138995.5	c.1198T>C	p.Tyr400His	missense_variant	Exon 12 of 35	ENST00000408978.9	NP_620482.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYO3B	ENST00000408978.9	c.1198T>C	p.Tyr400His	missense_variant	Exon 12 of 35	1	NM_138995.5	ENSP00000386213.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000401 AC: 1 AN: 249174 Hom.: 0 AF XY: 0.00000740 AC XY: 1 AN XY: 135158

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000885

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000198 AC: 29 AN: 1461106 Hom.: 0 Cov.: 29 AF XY: 0.0000206 AC XY: 15 AN XY: 726902

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000261

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Feb 22, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1198T>C (p.Y400H) alteration is located in exon 12 (coding exon 12) of the MYO3B gene. This alteration results from a T to C substitution at nucleotide position 1198, causing the tyrosine (Y) at amino acid position 400 to be replaced by a histidine (H). 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	0.94
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.55	.;D;D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D;D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Pathogenic	0.88	D
MutationAssessor	Pathogenic	3.4	M;M;.
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-4.9	D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D
Sift4G	Uncertain	0.012	.;.;D
Polyphen		1.0	D;D;.
Vest4		0.92
MutPred		0.91		Gain of disorder (P = 0.013);Gain of disorder (P = 0.013);.;
MVP		0.96
MPC		0.49
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.90
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.11		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: rs1260527308; hg19: chr2-171240232;