NM_000260.4:c.4018G>T

Variant names:

• chr11-77192144-G-T
• rs376291076
• NM_000260.4:c.4018G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PM5

The NM_000260.4(MYO7A):​c.4018G>T​(p.Ala1340Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,592 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1340T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MYO7A NM_000260.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.75
• Publications: 2 publications found

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]

MYO7A Gene-Disease associations (from GenCC):

• nonsyndromic genetic hearing loss

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• autosomal recessive nonsyndromic hearing loss 2

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Ambry Genetics, G2P
• Usher syndrome type 1

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet, PanelApp Australia
• Usher syndrome type 1B

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• autosomal dominant nonsyndromic hearing loss 11

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• autosomal dominant nonsyndromic hearing loss

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Usher syndrome type 2

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

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

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 12 uncertain in NM_000260.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-77192144-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2503056.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYO7A	NM_000260.4	c.4018G>T	p.Ala1340Ser	missense_variant	Exon 31 of 49	ENST00000409709.9	NP_000251.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYO7A	ENST00000409709.9	c.4018G>T	p.Ala1340Ser	missense_variant	Exon 31 of 49	1	NM_000260.4	ENSP00000386331.3
MYO7A	ENST00000458637.6	c.4018G>T	p.Ala1340Ser	missense_variant	Exon 31 of 49	1		ENSP00000392185.2
MYO7A	ENST00000409619.6	c.3985G>T	p.Ala1329Ser	missense_variant	Exon 32 of 50	1		ENSP00000386635.2
MYO7A	ENST00000458169.2	c.1561G>T	p.Ala521Ser	missense_variant	Exon 11 of 29	1		ENSP00000417017.2
MYO7A	ENST00000670577.1	n.1858G>T		non_coding_transcript_exon_variant	Exon 14 of 32			ENSP00000499323.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000402 AC: 1 AN: 248850 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000556

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461592 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727070

⚠️ 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: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53292

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111862

Other (OTH) AF: 0.00 AC: 0 AN: 60374

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000826 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

May 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 1340 of the MYO7A protein (p.Ala1340Ser). This variant is present in population databases (rs376291076, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with MYO7A-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MYO7A protein function with a negative 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. -

May 24, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
BayesDel_addAF	Benign	-0.057	T
BayesDel_noAF	Benign	-0.15
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.45	T;.;.;T
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.93	D;D;D;D
M_CAP	Uncertain	0.19	D
MetaRNN	Uncertain	0.65	D;D;D;D
MetaSVM	Uncertain	0.094	D
MutationAssessor	Benign	1.6	L;L;.;.
PhyloP100		7.7
PrimateAI	Uncertain	0.78	T
PROVEAN	Benign	-2.1	N;N;N;N
REVEL	Uncertain	0.44
Sift	Benign	0.16	T;T;T;T
Sift4G	Benign	0.14	T;T;T;T
Polyphen		1.0	D;.;.;.
Vest4		0.71
MutPred		0.45		Gain of phosphorylation at A1340 (P = 0.0264);Gain of phosphorylation at A1340 (P = 0.0264);.;.;
MVP		0.89
MPC		0.44
ClinPred		0.95	D
GERP RS		4.6
Varity_R		0.24
gMVP		0.43
Mutation Taster		=22/78	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: rs376291076; hg19: chr11-76903189;