rs1554049169

Variant names:

• chr5-87374245-T-C
• rs1554049169
• NM_002890.3:c.1859T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_002890.3(RASA1):​c.1859T>C​(p.Leu620Pro) 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 Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. L620L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: RASA1 NM_002890.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.95
• Publications: 0 publications found

Genes affected

RASA1 (HGNC:9871): (RAS p21 protein activator 1) The protein encoded by this gene is located in the cytoplasm and is part of the GAP1 family of GTPase-activating proteins. The gene product stimulates the GTPase activity of normal RAS p21 but not its oncogenic counterpart. Acting as a suppressor of RAS function, the protein enhances the weak intrinsic GTPase activity of RAS proteins resulting in the inactive GDP-bound form of RAS, thereby allowing control of cellular proliferation and differentiation. Mutations leading to changes in the binding sites of either protein are associated with basal cell carcinomas. Mutations also have been associated with hereditary capillary malformations (CM) with or without arteriovenous malformations (AVM) and Parkes Weber syndrome. Alternative splicing results in two isoforms where the shorter isoform, lacking the N-terminal hydrophobic region but retaining the same activity, appears to be abundantly expressed in placental but not adult tissues. [provided by RefSeq, May 2012]

CCNH (HGNC:1594): (cyclin H) The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. This cyclin forms a complex with CDK7 kinase and ring finger protein MAT1. The kinase complex is able to phosphorylate CDK2 and CDC2 kinases, thus functions as a CDK-activating kinase (CAK). This cyclin and its kinase partner are components of TFIIH, as well as RNA polymerase II protein complexes. They participate in two different transcriptional regulation processes, suggesting an important link between basal transcription control and the cell cycle machinery. A pseudogene of this gene is found on chromosome 4. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Nov 2010]

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.97

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RASA1	NM_002890.3	c.1859T>C	p.Leu620Pro	missense_variant	Exon 14 of 25	ENST00000274376.11	NP_002881.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RASA1	ENST00000274376.11	c.1859T>C	p.Leu620Pro	missense_variant	Exon 14 of 25	1	NM_002890.3	ENSP00000274376.6

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1450546 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 721730

African (AFR) AF: 0.00 AC: 0 AN: 33268

American (AMR) AF: 0.00 AC: 0 AN: 44508

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25738

East Asian (EAS) AF: 0.00 AC: 0 AN: 39208

South Asian (SAS) AF: 0.00 AC: 0 AN: 85112

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52534

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5710

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1104730

Other (OTH) AF: 0.00 AC: 0 AN: 59738

GnomAD4 genome Cov.: 30

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Capillary malformation-arteriovenous malformation syndrome Uncertain:1

Sep 26, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine with proline at codon 620 of the RASA1 protein (p.Leu620Pro). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and proline. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with RASA1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

Cardiovascular phenotype Uncertain:1

Aug 08, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.L620P variant (also known as c.1859T>C), located in coding exon 14 of the RASA1 gene, results from a T to C substitution at nucleotide position 1859. The leucine at codon 620 is replaced by proline, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.91	D;.;.;.
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Pathogenic	0.34	D
MetaRNN	Pathogenic	0.97	D;D;D;D
MetaSVM	Uncertain	0.32	D
MutationAssessor	Uncertain	2.3	M;.;.;.
PhyloP100		7.9
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-4.7	D;D;D;D
REVEL	Pathogenic	0.89
Sift	Uncertain	0.0010	D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0	D;D;.;D
Vest4		0.97
MutPred		0.89		Loss of stability (P = 0.0371);.;.;.;
MVP		0.98
MPC		2.3
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.93
gMVP		0.95
Mutation Taster		=13/87	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: rs1554049169; hg19: chr5-86670062;