7-6374772-T-G

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1_Strong PM2 PP3_Strong

The NM_006908.5(RAC1):c.35+2T>G variant causes a splice donor change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: RAC1 NM_006908.5 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.18

Genes affected

RAC1 (HGNC:9801): (Rac family small GTPase 1) The protein encoded by this gene is a GTPase which belongs to the RAS superfamily of small GTP-binding proteins. Members of this superfamily appear to regulate a diverse array of cellular events, including the control of cell growth, cytoskeletal reorganization, and the activation of protein kinases. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Mar 2009]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.41968912 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.8, offset of -21, new splice context is: caaGTgtgt. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RAC1	NM_006908.5	c.35+2T>G		splice_donor_variant		ENST00000348035.9
RAC1	NM_018890.4	c.35+2T>G		splice_donor_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RAC1	ENST00000348035.9	c.35+2T>G		splice_donor_variant		1	NM_006908.5	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Sep 28, 2022

Variant summary: RAC1 c.35+2T>G is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes the canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 22346 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. Loss of function variants in RAC1 have not been associated with Intellectual Disability, Autosomal Dominant 48 in HGMD. To our knowledge, no occurrence of c.35+2T>G in individuals affected with Intellectual Disability, Autosomal Dominant 48 and no experimental evidence demonstrating its impact on protein function have been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
Cadd	Pathogenic	34
Dann	Benign	0.96
Eigen	Pathogenic	0.78
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Benign	0.28	N
MutationTaster	Benign	1.0	D;D
GERP RS		3.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.79		Position offset: -23
DS_DL_spliceai		0.99		Position offset: -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: chr7-6414403;