2-197402636-T-C

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM5

The NM_012433.4(SF3B1):c.1997A>G(p.Lys666Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,613,940 control chromosomes in the GnomAD database, with no homozygous occurrence. There is a variant allele frequency bias in the population database for this variant (GnomAdExome4), which may indicate mosaicism or somatic mutations in the reference population data. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K666N) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

SF3B1
NM_012433.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 7.86

Publications

79 publications found

Variant links:

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]

SF3B1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM5

Other missense variant is known to change same aminoacid residue: Variant chr2-197402635-C-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 219098.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein
SF3B1	NM_012433.4 link	c.1997A>G	p.Lys666Arg	missense_variant	Exon 14 of 25	ENST00000335508.11	NP_036565.2
SF3B1	XM_047443838.1 link	c.1559A>G	p.Lys520Arg	missense_variant	Exon 11 of 22		XP_047299794.1
SF3B1	XM_047443839.1 link	c.1559A>G	p.Lys520Arg	missense_variant	Exon 11 of 22		XP_047299795.1
SF3B1	XM_047443840.1 link	c.1997A>G	p.Lys666Arg	missense_variant	Exon 14 of 22		XP_047299796.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SF3B1	ENST00000335508.11 link	c.1997A>G	p.Lys666Arg	missense_variant	Exon 14 of 25	1	NM_012433.4	ENSP00000335321.6

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152220

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000199

AC:

AN:

251366

AF XY:

0.0000368

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000462

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000103

AC:

AN:

1461720

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

727172

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33472

American (AMR)

AF:

0.0000224

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.0000562

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000809

AC:

AN:

1111870

Other (OTH)

AF:

0.0000166

AC:

AN:

60388

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000000298705), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.348

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152220

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74382

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41464

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000192

AC:

AN:

5204

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68024

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.450

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Mar 04, 2025

Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Myelodysplastic syndrome

Uncertain:1

Mar 20, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.67

BayesDel_addAF

Uncertain

0.11

BayesDel_noAF

Uncertain

0.0

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.57

Eigen

Uncertain

0.55

Eigen_PC

Uncertain

0.61

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

M_CAP

Benign

0.020

MetaRNN

Uncertain

0.67

MetaSVM

Benign

-0.64

MutationAssessor

Benign

1.2

PhyloP100

7.9

PrimateAI

Pathogenic

0.89

PROVEAN

Uncertain

-2.9

REVEL

Uncertain

0.44

Sift

Benign

0.17

Sift4G

Benign

0.27

Polyphen

0.93

Vest4

0.72

MutPred

0.52

Loss of loop (P = 0.0022);

MVP

0.76

MPC

2.0

ClinPred

0.75

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.8

Varity_R

0.80

gMVP

0.76

Mutation Taster

=20/80

disease causing (ClinVar)

(source)

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over