rs397516304

chr11-77190115-G-GC

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000260.4(MYO7A):c.3728dup(p.Pro1244AlafsTer64) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,262 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Q1242Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: MYO7A NM_000260.4 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.44

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-77190115-G-GC is Pathogenic according to our data. Variant chr11-77190115-G-GC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 43219.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYO7A	NM_000260.4	c.3728dup	p.Pro1244AlafsTer64	frameshift_variant	29/49	ENST00000409709.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYO7A	ENST00000409709.9	c.3728dup	p.Pro1244AlafsTer64	frameshift_variant	29/49	1	NM_000260.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152262 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152262 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74388

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Usher syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

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

Feb 20, 2023

Variant summary: MYO7A c.3728dupC (p.Pro1244AlafsX64) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been reported in HGMD in association with Retinitis pigmentosa, Deafness, non-syndromic, autosomal recessive and Usher syndrome. The variant was absent in 183422 control chromosomes. To our knowledge, no occurrence of c.3728dupC in individuals affected with Usher Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 22, 2023

This sequence change creates a premature translational stop signal (p.Pro1244Alafs*64) in the MYO7A gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MYO7A are known to be pathogenic (PMID: 8900236, 25404053). This variant is not present in population databases (gnomAD no frequency). 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: 43219). For these reasons, this variant has been classified as Pathogenic. -

Rare genetic deafness Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Aug 13, 2010

The Pro1244fs variant in MYO7A has not been reported in the literature nor previ ously identified by our laboratory. However, this variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at codon 1244 and leads to a premature stop codon 64 codons downstream. This alteration i s then predicted to lead to a truncated or absent protein. In summary, this vari ant meets our criteria to be classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

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: rs397516304; hg19: chr11-76901160;