11-77179855-C-T

Variant names:

• chr11-77179855-C-T
• rs797044493
• NM_000260.4:c.2488C>T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000260.4(MYO7A):​c.2488C>T​(p.Arg830Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000201 in 1,389,642 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: 34)
  • Exomes 𝑓: 0.000020 (0 hom.)
• Consequence: MYO7A NM_000260.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 6.03

Genes affected

MYO7A (HGNC:7606): (myosin VIIA) This gene is a member of the myosin gene family. Myosins are mechanochemical proteins characterized by the presence of a motor domain, an actin-binding domain, a neck domain that interacts with other proteins, and a tail domain that serves as an anchor. This gene encodes an unconventional myosin with a very short tail. Defects in this gene are associated with the mouse shaker-1 phenotype and the human Usher syndrome 1B which are characterized by deafness, reduced vestibular function, and (in human) retinal degeneration. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2008]

ACMG classification

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, 0.905

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYO7A	NM_000260.4	c.2488C>T	p.Arg830Cys	missense_variant	Exon 21 of 49	ENST00000409709.9	NP_000251.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYO7A	ENST00000409709.9	c.2488C>T	p.Arg830Cys	missense_variant	Exon 21 of 49	1	NM_000260.4	ENSP00000386331.3
MYO7A	ENST00000458637.6	c.2488C>T	p.Arg830Cys	missense_variant	Exon 21 of 49	1		ENSP00000392185.2
MYO7A	ENST00000409619.6	c.2455C>T	p.Arg819Cys	missense_variant	Exon 22 of 50	1		ENSP00000386635.2
MYO7A	ENST00000458169.2	c.31C>T	p.Arg11Cys	missense_variant	Exon 1 of 29	1		ENSP00000417017.2
MYO7A	ENST00000670577.1	n.328C>T		non_coding_transcript_exon_variant	Exon 4 of 32			ENSP00000499323.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD3 exomes AF: 0.0000144 AC: 2 AN: 139192 Hom.: 0 AF XY: 0.0000265 AC XY: 2 AN XY: 75372

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: 0.000109

Gnomad NFE exome AF: 0.0000188

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000201 AC: 28 AN: 1389642 Hom.: 0 Cov.: 31 AF XY: 0.0000248 AC XY: 17 AN XY: 685792

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000280

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000280

Gnomad4 SAS exome AF: 0.0000126

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000232

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Sep 04, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Arg830Cys variant in MYO7A has not been previously reported in individuals w ith hearing loss and data from large population studies is insufficient to asses s the frequency of this variant. Computational prediction tools and conservation analysis suggest that this variant may impact the protein, though this informat ion is not predictive enough to determine pathogenicity. In summary, the clinica l significance of the Arg830Cys variant is uncertain. -

Usher syndrome type 1;C1838701:Autosomal recessive nonsyndromic hearing loss 2 Uncertain:1

Oct 19, 2017

Counsyl

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Usher syndrome type 1B Uncertain:1

Mar 10, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided Uncertain:1

Sep 15, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 830 of the MYO7A protein (p.Arg830Cys). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with MYO7A-related conditions. ClinVar contains an entry for this variant (Variation ID: 164681). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt MYO7A protein function with a positive predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.44
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.49	T;T;.;.;.;D
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D
M_CAP	Pathogenic	0.60	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.9	H;.;H;.;.;.
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-7.8	D;.;D;D;.;D
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D;.;D;D;.;D
Sift4G	Pathogenic	0.0010	D;D;D;D;.;D
Polyphen		1.0	D;.;.;.;.;.
Vest4		0.87
MutPred		0.64		Gain of methylation at K831 (P = 0.023);Gain of methylation at K831 (P = 0.023);Gain of methylation at K831 (P = 0.023);.;.;.;
MVP		0.97
MPC		0.54
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.95
gMVP		0.79

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: rs797044493; hg19: chr11-76890901;