17-74922973-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_173477.5(USH1G):c.101C>A(p.Thr34Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000045 in 1,556,916 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T34S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000043 (0 hom.)
• Consequence: USH1G NM_173477.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.15

Genes affected

USH1G (HGNC:16356): (USH1 protein network component sans) This gene encodes a protein that contains three ankyrin domains, a class I PDZ-binding motif and a sterile alpha motif. The encoded protein interacts with harmonin, which is associated with Usher syndrome type 1C. This protein plays a role in the development and maintenance of the auditory and visual systems and functions in the cohesion of hair bundles formed by inner ear sensory cells. Mutations in this gene are associated with Usher syndrome type 1G (USH1G). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2013]

OTOP2 (HGNC:19657): (otopetrin 2) Predicted to enable proton channel activity. Predicted to be involved in proton transmembrane transport. Predicted to be located in plasma membrane. Predicted to be integral component of membrane. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.889

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
USH1G	NM_173477.5	c.101C>A	p.Thr34Asn	missense_variant	1/3	ENST00000614341.5
USH1G	NM_001282489.3	c.-156C>A		5_prime_UTR_variant	1/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
USH1G	ENST00000614341.5	c.101C>A	p.Thr34Asn	missense_variant	1/3	1	NM_173477.5	P1
OTOP2	ENST00000580223.2	c.-292G>T		5_prime_UTR_variant	1/5	1
USH1G	ENST00000579243.1	c.101C>A	p.Thr34Asn	missense_variant, NMD_transcript_variant	1/3	2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152174 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000427 AC: 6 AN: 1404742 Hom.: 0 Cov.: 31 AF XY: 0.00000144 AC XY: 1 AN XY: 692986

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000271

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000125

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000278

Gnomad4 OTH exome AF: 0.0000172

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152174 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74330

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 02, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Not Available"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Not Available"). This variant has not been reported in the literature in individuals affected with USH1G-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 34 of the USH1G protein (p.Thr34Asn). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.88
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Benign	-0.090
Cadd	Pathogenic	29
Dann	Benign	0.94
DEOGEN2	Uncertain	0.48	T
Eigen	Pathogenic	0.72
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.96	D
M_CAP	Benign	0.051	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Benign	-0.36	T
MutationAssessor	Uncertain	2.7	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.79	T
Sift4G	Uncertain	0.0060	D
Polyphen		0.99	D
Vest4		0.88
MutPred		0.77		Loss of glycosylation at T34 (P = 0.095);
MVP		0.54
ClinPred		0.90	D
GERP RS		4.1
Varity_R		0.82
gMVP		0.88

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: rs887769493; hg19: chr17-72919068;