rs1554833178

Variant names:

• chr10-26143446-A-C
• rs1554833178
• NM_017433.5:c.2263-2A>C

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_017433.5(MYO3A):​c.2263-2A>C variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,456,768 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 0.0000021 (0 hom.)
• Consequence: MYO3A NM_017433.5 splice_acceptor, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.32
• Publications: 0 publications found

Genes affected

MYO3A (HGNC:7601): (myosin IIIA) The protein encoded by this gene belongs to the myosin superfamily. Myosins are actin-dependent motor proteins and are categorized into conventional myosins (class II) and unconventional myosins (classes I and III through XV) based on their variable C-terminal cargo-binding domains. Class III myosins, such as this one, have a kinase domain N-terminal to the conserved N-terminal motor domains and are expressed in photoreceptors. The protein encoded by this gene plays an important role in hearing in humans. Three different recessive, loss of function mutations in the encoded protein have been shown to cause nonsyndromic progressive hearing loss. Expression of this gene is highly restricted, with the strongest expression in retina and cochlea. [provided by RefSeq, Jul 2008]

MYO3A Gene-Disease associations (from GenCC):

• autosomal recessive nonsyndromic hearing loss 30

  Inheritance: AR, SD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Ambry Genetics
• nonsyndromic genetic hearing loss

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• hearing loss, autosomal dominant 90

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 10-26143446-A-C is Pathogenic according to our data. Variant chr10-26143446-A-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 517589.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYO3A	NM_017433.5	c.2263-2A>C		splice_acceptor_variant, intron_variant	Intron 20 of 34	ENST00000642920.2	NP_059129.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYO3A	ENST00000642920.2	c.2263-2A>C		splice_acceptor_variant, intron_variant	Intron 20 of 34		NM_017433.5	ENSP00000495965.1
MYO3A	ENST00000543632.5	c.1776+46764A>C		intron_variant	Intron 16 of 16	1		ENSP00000445909.1
MYO3A	ENST00000642197.1	n.2467-2A>C		splice_acceptor_variant, intron_variant	Intron 20 of 26
MYO3A	ENST00000647478.1	n.*258-2A>C		splice_acceptor_variant, intron_variant	Intron 18 of 29			ENSP00000493932.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1456768 Hom.: 0 Cov.: 31 AF XY: 0.00000276 AC XY: 2 AN XY: 725040

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33368

American (AMR) AF: 0.00 AC: 0 AN: 44690

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26088

East Asian (EAS) AF: 0.00 AC: 0 AN: 39600

South Asian (SAS) AF: 0.00 AC: 0 AN: 86104

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53386

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.00000271 AC: 3 AN: 1107558

Other (OTH) AF: 0.00 AC: 0 AN: 60216

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000000000000888178), which strongly suggests a high chance of mosaicism in these individuals.

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

Sep 12, 2017

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2263-2A>C variant in MYO3A has not been previously reported in individuals with hearing loss or in large population studies. This variant occurs in the in variant region (+/- 1,2) of the splice consensus sequence and is predicted to ca use altered splicing leading to an abnormal or absent protein. Loss of MYO3A fun ction is a molecular mechanism for autosomal recessive hearing loss. In summary, although additional studies are required to fully establish its clinical signif icance, the c.2263-2A>C variant is likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.040
CADD	Pathogenic	26
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.3
GERP RS		6.0
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.99		Position offset: 2

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

Other links and lift over

dbSNP: rs1554833178; hg19: chr10-26432375;