rs1555076948

Positions:

• chr11-77172747-G-A
• chr11-77172747-G-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_Moderate PM2 PP3_Strong PP5_Very_Strong

The NM_000260.4(MYO7A):​c.1798-1G>A variant causes a splice acceptor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000285 in 1,403,254 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 33)
  • Exomes 𝑓: 0.0000029 (0 hom.)
• Consequence: MYO7A NM_000260.4 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 9.41

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 16 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.020607702 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7, offset of 1, new splice context is: ctgccgtccgtccccccaAGgcg. Cryptic site results in frameshift 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
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 11-77172747-G-A is Pathogenic according to our data. Variant chr11-77172747-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 557873.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-77172747-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYO7A	NM_000260.4	c.1798-1G>A		splice_acceptor_variant		ENST00000409709.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYO7A	ENST00000409709.9	c.1798-1G>A		splice_acceptor_variant		1	NM_000260.4
MYO7A	ENST00000409619.6	c.1765-1G>A		splice_acceptor_variant		1
MYO7A	ENST00000458637.6	c.1798-1G>A		splice_acceptor_variant		1		P1
MYO7A	ENST00000669443.1	c.162-1G>A		splice_acceptor_variant

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000285 AC: 4 AN: 1403254 Hom.: 0 Cov.: 31 AF XY: 0.00000144 AC XY: 1 AN XY: 692766

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: 0.00000370

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000508 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

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

Apr 13, 2018

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Oct 28, 2022

For these reasons, this variant has been classified as 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: 557873). Disruption of this splice site has been observed in individuals with Usher syndrome (PMID: 27460420; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 15 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). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D;D;D
GERP RS		4.8

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.83		Position offset: 2
DS_AL_spliceai		0.98		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: rs1555076948; hg19: chr11-76883793;