2-135052326-G-A

Variant names:

• chr2-135052326-G-A
• NM_012233.3:c.18+1G>A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_012233.3(RAB3GAP1):​c.18+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.000000684 in 1,461,710 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: RAB3GAP1 NM_012233.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.90

Genes affected

RAB3GAP1 (HGNC:17063): (RAB3 GTPase activating protein catalytic subunit 1) This gene encodes the catalytic subunit of a Rab GTPase activating protein. The encoded protein forms a heterodimer with a non-catalytic subunit to specifically regulate the activity of members of the Rab3 subfamily of small G proteins. This protein mediates the hydrolysis of GTP bound Rab3 to the GDP bound form. Mutations in this gene are associated with Warburg micro syndrome. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Feb 2010]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.4, offset of -5, new splice context is: acaGTgaga. Cryptic site results in frameshift 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RAB3GAP1	NM_012233.3	c.18+1G>A		splice_donor_variant, intron_variant	Intron 1 of 23	ENST00000264158.13	NP_036365.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RAB3GAP1	ENST00000264158.13	c.18+1G>A		splice_donor_variant, intron_variant	Intron 1 of 23	1	NM_012233.3	ENSP00000264158.8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461710 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727140

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

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.16
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Benign	0.69	D
GERP RS		4.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.42		Position offset: -6
DS_DL_spliceai		0.97		Position offset: -1

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: chr2-135809896;