17-18121822-AC-A

Position:

• chr17-18121822-AC-A

Variant summary

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

The NM_016239.4(MYO15A):​c.3026del​(p.Pro1009LeufsTer49) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,460,586 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: MYO15A NM_016239.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: -1.19

Genes affected

MYO15A (HGNC:7594): (myosin XVA) This gene encodes an unconventional myosin. This protein differs from other myosins in that it has a long N-terminal extension preceding the conserved motor domain. Studies in mice suggest that this protein is necessary for actin organization in the hair cells of the cochlea. Mutations in this gene have been associated with profound, congenital, neurosensory, nonsyndromal deafness. This gene is located within the Smith-Magenis syndrome region on chromosome 17. Read-through transcripts containing an upstream gene and this gene have been identified, but they are not thought to encode a fusion protein. Several alternatively spliced transcript variants have been described, but their full length sequences have not been determined. [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 17-18121822-AC-A is Pathogenic according to our data. Variant chr17-18121822-AC-A is described in ClinVar as [Pathogenic]. Clinvar id is 506256.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYO15A	NM_016239.4	c.3026del	p.Pro1009LeufsTer49	frameshift_variant	2/66	ENST00000647165.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYO15A	ENST00000647165.2	c.3026del	p.Pro1009LeufsTer49	frameshift_variant	2/66		NM_016239.4	P1
MYO15A	ENST00000583079.1	n.2659del		non_coding_transcript_exon_variant	1/1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000403 AC: 1 AN: 247954 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 134994

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000892

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1460586 Hom.: 0 Cov.: 44 AF XY: 0.00000138 AC XY: 1 AN XY: 726580

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: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 25, 2023

This sequence change creates a premature translational stop signal (p.Pro1009Leufs*49) in the MYO15A gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MYO15A are known to be pathogenic (PMID: 17546645). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with MYO15A-related conditions. ClinVar contains an entry for this variant (Variation ID: 506256). 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

Dec 21, 2017

The p.Pro1009fs variant in MYO15A has not been previously reported in individual s with hearing loss, but has been identified in 1/111138 European chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org). Alt hough this variant has been seen in the general population, its frequency is low enough to be consistent with the carrier frequency for recessive nonsyndromic h earing loss. This variant is predicted to cause a frameshift, which alters the protein?s amino acid sequence beginning at position 1009 and leads to a prematur e termination codon 49 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein, and truncating variants in this regio n of the protein in individuals with hearing loss have been previously reported by our laboratory and in ClinVar. In summary, this variant meets criteria to be classified as pathogenic for hearing loss in an autosomal recessive manner based on the predicted impact of the variant. ACMG/AMP Criteria applied: PVS1, PM2, P M1. -

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: rs1555539827; hg19: chr17-18025136;