chr2-170383755-C-T

Variant names:

• chr2-170383755-C-T
• rs773289825
• NM_138995.5:c.1231C>T

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.1231C>T​(p.His411Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,554 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H411N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MYO3B NM_138995.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.88
• 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, 0.99

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYO3B	NM_138995.5	c.1231C>T	p.His411Tyr	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.1231C>T	p.His411Tyr	missense_variant	Exon 12 of 35	1	NM_138995.5	ENSP00000386213.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461554 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727092

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

African (AFR) AF: 0.00 AC: 0 AN: 33458

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111746

Other (OTH) AF: 0.0000331 AC: 2 AN: 60384

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.005674), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.57	.;D;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;D;D
M_CAP	Pathogenic	0.38	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	H;H;.
PhyloP100		7.9
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-5.9	D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	.;.;D
Polyphen		1.0	D;D;.
Vest4		0.93
MutPred		0.94		Loss of disorder (P = 0.0412);Loss of disorder (P = 0.0412);.;
MVP		0.99
MPC		0.46
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.93
gMVP		0.97
Mutation Taster		=53/47	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs773289825; hg19: chr2-171240265;