1-109603487-T-C

Position:

• chr1-109603487-T-C

Variant summary

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

The NM_001377295.2(GNAT2):​c.932A>G​(p.Asn311Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. N311D) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GNAT2 NM_001377295.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.93

Genes affected

GNAT2 (HGNC:4394): (G protein subunit alpha transducin 2) Transducin is a 3-subunit guanine nucleotide-binding protein (G protein) which stimulates the coupling of rhodopsin and cGMP-phoshodiesterase during visual impulses. The transducin alpha subunits in rods and cones are encoded by separate genes. This gene encodes the alpha subunit in cones. [provided by RefSeq, Jul 2008]

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, 0.888

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GNAT2	NM_001377295.2	c.932A>G	p.Asn311Ser	missense_variant	9/9	ENST00000679935.1
GNAT2	NM_001379232.1	c.932A>G	p.Asn311Ser	missense_variant	9/9
GNAT2	NM_005272.5	c.932A>G	p.Asn311Ser	missense_variant	8/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GNAT2	ENST00000679935.1	c.932A>G	p.Asn311Ser	missense_variant	9/9		NM_001377295.2	P1
GNAT2	ENST00000351050.8	c.932A>G	p.Asn311Ser	missense_variant	8/8	1		P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

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

Labcorp Genetics (formerly Invitae), Labcorp

Jan 19, 2021

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 sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. 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 GNAT2 protein function. This variant has not been reported in the literature in individuals with GNAT2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces asparagine with serine at codon 311 of the GNAT2 protein (p.Asn311Ser). The asparagine residue is highly conserved and there is a small physicochemical difference between asparagine and serine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.47
BayesDel_addAF	Uncertain	0.079	D
BayesDel_noAF	Benign	-0.12
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.68	D
Eigen	Pathogenic	0.70
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D
M_CAP	Benign	0.074	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Uncertain	0.49	D
MutationAssessor	Uncertain	2.3	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.73	T
PROVEAN	Uncertain	-4.2	D
REVEL	Pathogenic	0.77
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.012	D
Polyphen		0.97	D
Vest4		0.85
MutPred		0.68		Gain of disorder (P = 0.055);
MVP		0.96
MPC		0.81
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.70
gMVP		0.76

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-110146109;