2-197400802-A-T

Variant names:

• chr2-197400802-A-T
• rs788018
• NM_012433.4:c.2631T>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_012433.4(SF3B1):​c.2631T>A​(p.Gly877Gly) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. G877G) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SF3B1 NM_012433.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.494
• Publications: 48 publications found

Genes affected

SF3B1 (HGNC:10768): (splicing factor 3b subunit 1) This gene encodes subunit 1 of the splicing factor 3b protein complex. Splicing factor 3b, together with splicing factor 3a and a 12S RNA unit, forms the U2 small nuclear ribonucleoproteins complex (U2 snRNP). The splicing factor 3b/3a complex binds pre-mRNA upstream of the intron's branch site in a sequence independent manner and may anchor the U2 snRNP to the pre-mRNA. Splicing factor 3b is also a component of the minor U12-type spliceosome. The carboxy-terminal two-thirds of subunit 1 have 22 non-identical, tandem HEAT repeats that form rod-like, helical structures. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.54).
• BP7: Synonymous conserved (PhyloP=0.494 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SF3B1	NM_012433.4	c.2631T>A	p.Gly877Gly	synonymous_variant	Exon 18 of 25	ENST00000335508.11	NP_036565.2
SF3B1	XM_047443838.1	c.2193T>A	p.Gly731Gly	synonymous_variant	Exon 15 of 22		XP_047299794.1
SF3B1	XM_047443839.1	c.2193T>A	p.Gly731Gly	synonymous_variant	Exon 15 of 22		XP_047299795.1
SF3B1	XM_047443840.1	c.2631T>A	p.Gly877Gly	synonymous_variant	Exon 18 of 22		XP_047299796.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SF3B1	ENST00000335508.11	c.2631T>A	p.Gly877Gly	synonymous_variant	Exon 18 of 25	1	NM_012433.4	ENSP00000335321.6

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1460668 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 726756

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39650

South Asian (SAS) AF: 0.00 AC: 0 AN: 86228

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53300

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111056

Other (OTH) AF: 0.00 AC: 0 AN: 60368

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 29819

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.54
CADD	Benign	8.5
DANN	Benign	0.80
PhyloP100		0.49
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=79/21	polymorphism

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: rs788018; hg19: chr2-198265526;