14-30875085-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_004086.3(COCH):c.64G>A(p.Ala22Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000139 in 1,433,720 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: COCH NM_004086.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.25

Genes affected

COCH (HGNC:2180): (cochlin) The protein encoded by this gene is highly conserved in human, mouse, and chicken, showing 94% and 79% amino acid identity of human to mouse and chicken sequences, respectively. Hybridization to this gene was detected in spindle-shaped cells located along nerve fibers between the auditory ganglion and sensory epithelium. These cells accompany neurites at the habenula perforata, the opening through which neurites extend to innervate hair cells. This and the pattern of expression of this gene in chicken inner ear paralleled the histologic findings of acidophilic deposits, consistent with mucopolysaccharide ground substance, in temporal bones from DFNA9 (autosomal dominant nonsyndromic sensorineural deafness 9) patients. Mutations that cause DFNA9 have been reported in this gene. Alternative splicing results in multiple transcript variants encoding the same protein. Additional splice variants encoding distinct isoforms have been described but their biological validities have not been demonstrated. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.13835782).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COCH	NM_004086.3	c.64G>A	p.Ala22Thr	missense_variant	3/12	ENST00000396618.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COCH	ENST00000396618.9	c.64G>A	p.Ala22Thr	missense_variant	3/12	1	NM_004086.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000139 AC: 2 AN: 1433720 Hom.: 0 Cov.: 32 AF XY: 0.00000281 AC XY: 2 AN XY: 710968

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: 0.00000182

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 20, 2023

The c.64G>A (p.A22T) alteration is located in exon 3 (coding exon 2) of the COCH gene. This alteration results from a G to A substitution at nucleotide position 64, causing the alanine (A) at amino acid position 22 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.085
BayesDel_addAF	Benign	-0.093	T
BayesDel_noAF	Benign	-0.37
Cadd	Benign	18
Dann	Uncertain	0.99
Eigen	Benign	-0.55
Eigen_PC	Benign	-0.42
FATHMM_MKL	Benign	0.54	D
LIST_S2	Benign	0.28	T;.;.;T;T;T;T
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.14	T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	1.0	D;N;N;N
PrimateAI	Uncertain	0.60	T
PROVEAN	Benign	0.68	N;N;.;.;N;N;.
REVEL	Benign	0.095
Sift	Benign	0.64	T;T;.;.;T;D;.
Sift4G	Benign	0.45	T;T;.;.;T;T;.
Polyphen		0.51	.;P;P;.;.;.;P
Vest4		0.15
MutPred		0.21		Gain of glycosylation at A22 (P = 0.0388);Gain of glycosylation at A22 (P = 0.0388);Gain of glycosylation at A22 (P = 0.0388);Gain of glycosylation at A22 (P = 0.0388);Gain of glycosylation at A22 (P = 0.0388);Gain of glycosylation at A22 (P = 0.0388);Gain of glycosylation at A22 (P = 0.0388);
MVP		0.65
MPC		0.21
ClinPred		0.52	D
GERP RS		4.5
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.7
Varity_R		0.065
gMVP		0.067

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1325512875; hg19: chr14-31344291;