NM_000260.4:c.1903T>C

Variant names:

• chr11-77172853-T-C
• rs797044514
• NM_000260.4:c.1903T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM2 PM5 PP3_Strong PP5

The NM_000260.4(MYO7A):​c.1903T>C​(p.Cys635Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000714 in 1,399,818 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C635Y) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: MYO7A NM_000260.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:2
• Conservation: PhyloP100: 7.60
• Publications: 1 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 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-77172854-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2662469.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 11-77172853-T-C is Pathogenic according to our data. Variant chr11-77172853-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 179146.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYO7A	NM_000260.4	c.1903T>C	p.Cys635Arg	missense_variant	Exon 16 of 49	ENST00000409709.9	NP_000251.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYO7A	ENST00000409709.9	c.1903T>C	p.Cys635Arg	missense_variant	Exon 16 of 49	1	NM_000260.4	ENSP00000386331.3
MYO7A	ENST00000458637.6	c.1903T>C	p.Cys635Arg	missense_variant	Exon 16 of 49	1		ENSP00000392185.2
MYO7A	ENST00000409619.6	c.1870T>C	p.Cys624Arg	missense_variant	Exon 17 of 50	1		ENSP00000386635.2
MYO7A	ENST00000669443.1	c.265T>C	p.Cys89Arg	missense_variant	Exon 3 of 3			ENSP00000499530.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.14e-7 AC: 1 AN: 1399818 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 690486

African (AFR) AF: 0.00 AC: 0 AN: 31612

American (AMR) AF: 0.00 AC: 0 AN: 35748

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25174

East Asian (EAS) AF: 0.00 AC: 0 AN: 35762

South Asian (SAS) AF: 0.0000126 AC: 1 AN: 79238

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49254

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5696

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1079284

Other (OTH) AF: 0.00 AC: 0 AN: 58050

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:2

Dec 06, 2022

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Cys635Arg variant in MYO7A has been reported in 5 homozygous individuals with hearing loss and retinal dysfunction (Neuhaus 2017 PMID: 28944237, Kletke 2017 PMID: 27743452, LMM data, GeneDx pers. comm.). It was absent from large population studies. This variant has also been reported in ClinVar (Variation ID 179146). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM3, PM2_Supporting, PP3. -

Dec 10, 2019

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 28944237, 27743452) -

Jun 27, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 635 of the MYO7A protein (p.Cys635Arg). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of Usher syndrome type 1 (PMID: 27743452). ClinVar contains an entry for this variant (Variation ID: 179146). 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 expected to disrupt MYO7A protein function. 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. -

Usher syndrome Pathogenic:1

May 17, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MYO7A c.1903T>C (p.Cys635Arg) results in a non-conservative amino acid change located in the Myosin head, motor domain (IPR001609) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 155584 control chromosomes. c.1903T>C has been reported in the literature in homozygous individuals affected with Autosomal Recessive Usher Syndrome (Kletke_2017, Neuhaus_2017). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 27743452, 28944237). ClinVar contains an entry for this variant (Variation ID: 179146). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;D;.;.
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D;D;D;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.7	H;.;H;.
PhyloP100		7.6
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-11	D;.;D;D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;.;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;.;.;.
Vest4		0.98
MutPred		0.93		Gain of MoRF binding (P = 0.0206);Gain of MoRF binding (P = 0.0206);Gain of MoRF binding (P = 0.0206);.;
MVP		0.99
MPC		0.62
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.99
gMVP		0.96
Mutation Taster		=0/100	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: rs797044514; hg19: chr11-76883899;