1-155904496-A-T

Variant names:

• chr1-155904496-A-T
• rs869025194
• NM_006912.6:c.244T>A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_006912.6(RIT1):​c.244T>A​(p.Phe82Ile) 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. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F82C) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: RIT1 NM_006912.6 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 7.55
• Publications: 19 publications found

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]

RIT1 Gene-Disease associations (from GenCC):

• Noonan syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• Noonan syndrome 8

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia, Genomics England PanelApp

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PM1: In a hotspot region, there are 19 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_006912.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-155904495-A-C is described in ClinVar as Pathogenic. ClinVar VariationId is 372863.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.967
• PP5: Variant 1-155904496-A-T is Pathogenic according to our data. Variant chr1-155904496-A-T is described in ClinVar as Pathogenic. ClinVar VariationId is 183406.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006912.6. 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
	RIT1	NM_006912.6	MANE Select	c.244T>A	p.Phe82Ile	missense	Exon 5 of 6	NP_008843.1
	RIT1	NM_001256821.2		c.295T>A	p.Phe99Ile	missense	Exon 5 of 6	NP_001243750.1
	RIT1	NM_001256820.2		c.136T>A	p.Phe46Ile	missense	Exon 4 of 5	NP_001243749.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RIT1	ENST00000368323.8	TSL:1 MANE Select	c.244T>A	p.Phe82Ile	missense	Exon 5 of 6	ENSP00000357306.3
	RIT1	ENST00000609492.1	TSL:1	c.244T>A	p.Phe82Ile	missense	Exon 4 of 5	ENSP00000476612.1
	RIT1	ENST00000368322.7	TSL:3	c.295T>A	p.Phe99Ile	missense	Exon 5 of 6	ENSP00000357305.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Noonan syndrome 8 Pathogenic:3

Apr 11, 2023

Genome-Nilou Lab

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Aug 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces phenylalanine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 82 of the RIT1 protein (p.Phe82Ile). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with clinical features of Noonan syndrome (PMID: 26757980; Invitae). ClinVar contains an entry for this variant (Variation ID: 183406). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (Invitae) indicates that this missense variant is expected to disrupt RIT1 function with a positive predictive value of 95%. This variant disrupts the p.Phe82 amino acid residue in RIT1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 23791108, 24939608, 25049390, 26757980). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic.

Rady Children's Institute for Genomic Medicine, Rady Children's Hospital San Diego

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has been previously reported in the literature as c.244T>A (p.Phe82Ile) on the alternative transcript NM_006912.5. This variant has been previously reported as a heterozygous germline variant in one individual with Noonan Syndrome (PMID: 26757980). This variant has also been previously reported as a somatic variant in myeloid malignancies (PMID: 23765226). However, other variants affecting the same amino acid residue have been reported in ClinVar as Pathogenic variants (Variation ID: 183407, 183408, 372863, 694696, 181522, 370035). This variant is absent from the gnomAD population database and thus is presumed to be rare. The c.295T>A (p.Phe99Ile) variant affects a highly conserved amino acid and is predicted by multiple in silico tools to have a deleterious effect on protein function. Analysis of the parental samples was negative for the variant, indicating this variant likely occurred as a de novo event. Based on the available evidence, the c.295T>A (p.Phe99Ile) variant is classified as Pathogenic.

not provided Pathogenic:1

Sep 28, 2021

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26757980, 23765226)

Noonan syndrome Pathogenic:1

Service de Génétique Moléculaire, Hôpital Robert Debré

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	31
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.79	D
Eigen	Pathogenic	0.92
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.46	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	0.81	D
MutationAssessor	Pathogenic	3.6	H
PhyloP100		7.6
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-5.4	D
REVEL	Pathogenic	0.96
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.88
MutPred		0.87		Loss of catalytic residue at F82 (P = 0.078)
MVP		0.89
MPC		2.2
ClinPred		1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.95
gMVP		0.98
Mutation Taster		=2/98	disease causing

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

Other links and lift over

dbSNP: rs869025194; hg19: chr1-155874287;