1-155900431-C-T

Position:

• chr1-155900431-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_006912.6(RIT1):​c.617G>A​(p.Arg206Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,848 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign 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. R206S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: RIT1 NM_006912.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.89

Genes affected

RIT1 (HGNC:10023): (Ras like without CAAX 1) This gene encodes a member of a subfamily of Ras-related GTPases. The encoded protein is involved in regulating p38 MAPK-dependent signaling cascades related to cellular stress. This protein also cooperates with nerve growth factor to promote neuronal development and regeneration. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Feb 2012]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a chain GTP-binding protein Rit1 (size 218) in uniprot entity RIT1_HUMAN there are 54 pathogenic changes around while only 10 benign (84%) in NM_006912.6
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.111653745).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RIT1	NM_006912.6	c.617G>A	p.Arg206Lys	missense_variant	6/6	ENST00000368323.8
RIT1	NM_001256821.2	c.668G>A	p.Arg223Lys	missense_variant	6/6
RIT1	NM_001256820.2	c.509G>A	p.Arg170Lys	missense_variant	5/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RIT1	ENST00000368323.8	c.617G>A	p.Arg206Lys	missense_variant	6/6	1	NM_006912.6	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461848 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727226

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Noonan syndrome 8 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 14, 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. 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 RIT1 protein function. This variant has not been reported in the literature in individuals affected with RIT1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with lysine, which is basic and polar, at codon 206 of the RIT1 protein (p.Arg206Lys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.12	T
BayesDel_noAF	Benign	-0.41
CADD	Benign	21
DANN	Benign	0.96
DEOGEN2	Benign	0.20	T;.;.
Eigen	Benign	-0.18
Eigen_PC	Benign	0.056
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Benign	0.66	T;T;T
M_CAP	Benign	0.0090	T
MetaRNN	Benign	0.11	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	-0.46	N;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.73	T
PROVEAN	Benign	-0.86	N;N;N
REVEL	Benign	0.033
Sift	Benign	0.29	T;T;T
Sift4G	Benign	0.51	T;T;T
Polyphen		0.0010	B;.;.
Vest4		0.21
MutPred		0.34		Gain of sheet (P = 4e-04);.;.;
MVP		0.58
MPC		0.79
ClinPred		0.67	D
GERP RS		5.1
Varity_R		0.14
gMVP		0.69

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: rs138290726; hg19: chr1-155870222;