chr11-77147949-A-T

Variant names:

• chr11-77147949-A-T
• rs797044489
• NM_000260.4:c.284A>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PM5 PP3 PP5_Moderate

The NM_000260.4(MYO7A):​c.284A>T​(p.Tyr95Phe) variant causes a missense, splice region 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. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y95H) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYO7A NM_000260.4 missense, splice_region
• Scores: Splicing: ADA: 0.9938
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.32
• Publications: 0 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.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 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 chr11-77147949-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1199867.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant 11-77147949-A-T is Pathogenic according to our data. Variant chr11-77147949-A-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 164654.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.284A>T	p.Tyr95Phe	missense_variant, splice_region_variant	Exon 4 of 49	ENST00000409709.9	NP_000251.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYO7A	ENST00000409709.9	c.284A>T	p.Tyr95Phe	missense_variant, splice_region_variant	Exon 4 of 49	1	NM_000260.4	ENSP00000386331.3
MYO7A	ENST00000458637.6	c.284A>T	p.Tyr95Phe	missense_variant, splice_region_variant	Exon 4 of 49	1		ENSP00000392185.2
MYO7A	ENST00000409619.6	c.251A>T	p.Tyr84Phe	missense_variant, splice_region_variant	Exon 5 of 50	1		ENSP00000386635.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Rare genetic deafness Pathogenic:1

Dec 26, 2017

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Tyr95Phe variant in MYO7A has been identified in 1 child with hearing loss who was compound heterozygous with a pathogenic nonsense variant in MYO7A. Thes e variants segregated in an affected sibling. Neither sibling was reported to ha ve balance problems or delayed walking, though formal eye evaluations had not oc curred yet at the time of testing. This variant was absent from large population studies. A different amino acid change at the same position, p.Tyr95Cys, was id entified in trans with a nonsense variant in MYO7A in two siblings with Usher sy ndrome (Bujakowska 2014). This variant is located in the last three bases of the exon, which is part of the 5? splice region. Computational tools do not predict altered splicing. However computational prediction tools and conservation anal yses for the amino acid change suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. I n summary, although additional studies are required to fully establish its clini cal significance and to determine whether it could cause Usher syndrome or atypi cal Usher syndrome, this variant is likely pathogenic for autosomal recessive he aring loss. ACMG/AMP Criteria applied: PM2, PM3, PM5, PP3. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.48
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.020
CADD	Pathogenic	32
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D;D;.;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.97	D;D;D;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Pathogenic	0.98	D;D;D;D
MetaSVM	Uncertain	0.74	D
MutationAssessor	Pathogenic	3.1	M;.;M;.
PhyloP100		9.3
PrimateAI	Pathogenic	0.84	D
PROVEAN	Uncertain	-3.4	D;.;D;D
REVEL	Pathogenic	0.88
Sift	Pathogenic	0.0	D;.;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;.;.;.
Vest4		0.80
MutPred		0.93		Loss of catalytic residue at I94 (P = 0.0632);Loss of catalytic residue at I94 (P = 0.0632);Loss of catalytic residue at I94 (P = 0.0632);.;
MVP		0.86
MPC		0.44
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.80
gMVP		0.69
Mutation Taster		=20/80	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.84
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: rs797044489; hg19: chr11-76858995;