NM_016239.4:c.6657G>C

Variant names:

• chr17-18148176-G-C
• rs727504708
• NM_016239.4:c.6657G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The NM_016239.4(MYO15A):​c.6657G>C​(p.Lys2219Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,468 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. K2219K) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: MYO15A NM_016239.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.467
• Publications: 1 publications found

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]

MYO15A Gene-Disease associations (from GenCC):

• autosomal recessive nonsyndromic hearing loss 3

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), PanelApp Australia
• nonsyndromic genetic hearing loss

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

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_016239.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.34776223).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYO15A	NM_016239.4	c.6657G>C	p.Lys2219Asn	missense_variant	Exon 31 of 66	ENST00000647165.2	NP_057323.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYO15A	ENST00000647165.2	c.6657G>C	p.Lys2219Asn	missense_variant	Exon 31 of 66		NM_016239.4	ENSP00000495481.1
MYO15A	ENST00000578999.1	n.242G>C		non_coding_transcript_exon_variant	Exon 2 of 4	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461468 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727044

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53010

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1112006

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

May 25, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 2219 of the MYO15A protein (p.Lys2219Asn). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MYO15A protein function. This variant has not been reported in the literature in individuals affected with MYO15A-related conditions. This variant is not present in population databases (gnomAD no frequency).

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.46
BayesDel_addAF	Benign	-0.058	T
BayesDel_noAF	Benign	-0.32
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.17	T;D;D
Eigen	Uncertain	0.42
Eigen_PC	Uncertain	0.34
FATHMM_MKL	Uncertain	0.81	D
LIST_S2	Benign	0.75	T;.;T
M_CAP	Uncertain	0.22	D
MetaRNN	Benign	0.35	T;T;T
MetaSVM	Uncertain	0.49	D
MutationAssessor	Benign	0.0	.;M;M
PhyloP100		0.47
PrimateAI	Uncertain	0.51	T
PROVEAN	Benign	0.0	.;D;.
REVEL	Benign	0.0
Sift	Pathogenic	0.0	.;D;.
Sift4G	Pathogenic	0.0010	D;D;.
Vest4		0.53
ClinPred		0.93	D
GERP RS		3.1
Varity_R		0.34
gMVP		0.89
Mutation Taster		=56/44	polymorphism

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

Other links and lift over

dbSNP: rs727504708; hg19: chr17-18051490;