rs397516283

Positions:

• chr11-77160283-G-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_000260.4(MYO7A):​c.1200+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: MYO7A NM_000260.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.95

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 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.01790012 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.1, offset of -21, new splice context is: gacGTgcgc. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-77160283-G-A is Pathogenic according to our data. Variant chr11-77160283-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 43138.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYO7A	NM_000260.4	c.1200+1G>A		splice_donor_variant, intron_variant		ENST00000409709.9	NP_000251.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYO7A	ENST00000409709.9	c.1200+1G>A		splice_donor_variant, intron_variant		1	NM_000260.4	ENSP00000386331.3
MYO7A	ENST00000458637.6	c.1200+1G>A		splice_donor_variant, intron_variant		1		ENSP00000392185.2
MYO7A	ENST00000409619.6	c.1167+1G>A		splice_donor_variant, intron_variant		1		ENSP00000386635.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 7.12e-7 AC: 1 AN: 1404928 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 693710

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.23e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Likely pathogenic, criteria provided, single submitter

clinical testing

Counsyl

Jan 23, 2018

- -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 26, 2021

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 43138). This variant has not been reported in the literature in individuals affected with MYO7A-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change affects a donor splice site in intron 11 of the MYO7A gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in MYO7A are known to be pathogenic (PMID: 8900236, 25404053). -

Rare genetic deafness Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Aug 17, 2010

The 1200+1G>A variant in MYO7A has not been reported in the literature nor previ ously identified by our laboratory. The 1200+1G>A variant is predicted to cause abnormal splicing because the nucleotide substitution occurs in the invariant re gion of the splice consensus sequence. Therefore, this variant meets our criteri a to be classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs397516283; hg19: chr11-76871329;