chr2-135126250-G-C

Variant names:

• chr2-135126250-G-C
• rs587777152
• NM_012233.3:c.899+1G>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_012233.3(RAB3GAP1):​c.899+1G>C variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,456,286 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: 0.0000014 (0 hom.)
• Consequence: RAB3GAP1 NM_012233.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.02
• Publications: 0 publications found

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]

RAB3GAP1 Gene-Disease associations (from GenCC):

• Warburg micro syndrome

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Warburg micro syndrome 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• cataract-intellectual disability-hypogonadism syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.02342159 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.6, offset of 4, new splice context is: taaGTatgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_012233.3. 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
	RAB3GAP1	NM_012233.3	MANE Select	c.899+1G>C		splice_donor intron	N/A	NP_036365.1
	RAB3GAP1	NM_001172435.2		c.899+1G>C		splice_donor intron	N/A	NP_001165906.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RAB3GAP1	ENST00000264158.13	TSL:1 MANE Select	c.899+1G>C		splice_donor intron	N/A	ENSP00000264158.8
	RAB3GAP1	ENST00000442034.5	TSL:1	c.899+1G>C		splice_donor intron	N/A	ENSP00000411418.1
	RAB3GAP1	ENST00000686114.1		n.913G>C		non_coding_transcript_exon	Exon 10 of 18

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1456286 Hom.: 0 Cov.: 30 AF XY: 0.00000276 AC XY: 2 AN XY: 724878

African (AFR) AF: 0.00 AC: 0 AN: 33350

American (AMR) AF: 0.00 AC: 0 AN: 44692

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26088

East Asian (EAS) AF: 0.00 AC: 0 AN: 39568

South Asian (SAS) AF: 0.00 AC: 0 AN: 86054

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53388

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000181 AC: 2 AN: 1107210

Other (OTH) AF: 0.00 AC: 0 AN: 60174

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		8.0
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.98		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs587777152; hg19: chr2-135883820;