16-21722919-G-T

Variant names:

• chr16-21722919-G-T
• rs143993346
• NM_144672.4:c.1821G>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_144672.4(OTOA):​c.1821G>T​(p.Ala607Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,828 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. A607A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: OTOA NM_144672.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.856
• Publications: 0 publications found

Genes affected

OTOA (HGNC:16378): (otoancorin) The protein encoded by this gene is specifically expressed in the inner ear, and is located at the interface between the apical surface of the inner ear sensory epithelia and their overlying acellular gels. It is prposed that this protein is involved in the attachment of the inner ear acellular gels to the apical surface of the underlying nonsensory cells. Mutations in this gene are associated with autosomal recessive deafness type 22 (DFNB22). Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2009]

OTOA Gene-Disease associations (from GenCC):

• autosomal recessive nonsyndromic hearing loss 22

  Inheritance: AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Laboratory for Molecular Medicine, G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• 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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_144672.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	OTOA	NM_144672.4	MANE Select	c.1821G>T	p.Ala607Ala	synonymous	Exon 18 of 29	NP_653273.3
	OTOA	NM_001161683.2		c.1584G>T	p.Ala528Ala	synonymous	Exon 13 of 24	NP_001155155.1
	OTOA	NM_170664.3		c.849G>T	p.Ala283Ala	synonymous	Exon 8 of 19	NP_733764.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	OTOA	ENST00000646100.2	MANE Select	c.1821G>T	p.Ala607Ala	synonymous	Exon 18 of 29	ENSP00000496564.2
	OTOA	ENST00000388958.8	TSL:1	c.1821G>T	p.Ala607Ala	synonymous	Exon 17 of 28	ENSP00000373610.3
	OTOA	ENST00000286149.8	TSL:5	c.1863G>T	p.Ala621Ala	synonymous	Exon 17 of 28	ENSP00000286149.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461828 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727226

⚠️ 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: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.0000756 AC: 3 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111960

Other (OTH) AF: 0.00 AC: 0 AN: 60394

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00383038), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.40
CADD	Benign	2.8
DANN	Benign	0.66
PhyloP100		-0.86

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.23		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.23		Position offset: -14

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

Other links and lift over

dbSNP: rs143993346; hg19: chr16-21734240;