NM_030962.4:c.2474A>G

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BS1_Supporting

The NM_030962.4(SBF2):​c.2474A>G​(p.Lys825Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000936 in 1,613,838 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000099 ( 1 hom. )

Consequence

SBF2
NM_030962.4 missense

Scores

2
8
9

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 8.02

Publications

0 publications found
Variant links:
Genes affected
SBF2 (HGNC:2135): (SET binding factor 2) This gene encodes a pseudophosphatase and member of the myotubularin-related protein family. This gene maps within the CMT4B2 candidate region of chromosome 11p15 and mutations in this gene have been associated with Charcot-Marie-Tooth Disease, type 4B2. [provided by RefSeq, Jul 2008]
SBF2 Gene-Disease associations (from GenCC):
  • Charcot-Marie-Tooth disease type 4B2
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P, ClinGen, Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BS1
Variant frequency is greater than expected in population nfe. GnomAdExome4 allele frequency = 0.0000985 (144/1461740) while in subpopulation NFE AF = 0.000119 (132/1111926). AF 95% confidence interval is 0.000102. There are 1 homozygotes in GnomAdExome4. There are 72 alleles in the male GnomAdExome4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SBF2NM_030962.4 linkc.2474A>G p.Lys825Arg missense_variant Exon 20 of 40 ENST00000256190.13 NP_112224.1 Q86WG5-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SBF2ENST00000256190.13 linkc.2474A>G p.Lys825Arg missense_variant Exon 20 of 40 1 NM_030962.4 ENSP00000256190.8 Q86WG5-1

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152098
Hom.:
0
Cov.:
32
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:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000103
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000107
AC:
27
AN:
251390
AF XY:
0.000118
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000924
Gnomad NFE exome
AF:
0.000202
Gnomad OTH exome
AF:
0.000326
GnomAD4 exome
AF:
0.0000985
AC:
144
AN:
1461740
Hom.:
1
Cov.:
32
AF XY:
0.0000990
AC XY:
72
AN XY:
727168
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39668
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.0000749
AC:
4
AN:
53412
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.000119
AC:
132
AN:
1111926
Other (OTH)
AF:
0.000132
AC:
8
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.460
Heterozygous variant carriers
0
8
16
23
31
39
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000460
AC:
7
AN:
152098
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74300
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41410
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3462
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000103
AC:
7
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.432
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000198
Hom.:
0
Bravo
AF:
0.0000416
ExAC
AF:
0.000115
AC:
14
EpiCase
AF:
0.000218
EpiControl
AF:
0.000296

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Nov 12, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.2474A>G (p.K825R) alteration is located in exon 20 (coding exon 20) of the SBF2 gene. This alteration results from a A to G substitution at nucleotide position 2474, causing the lysine (K) at amino acid position 825 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Charcot-Marie-Tooth disease type 4B2 Uncertain:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not provided Uncertain:1
Apr 10, 2019
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Charcot-Marie-Tooth disease type 4 Uncertain:1
Jan 27, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 825 of the SBF2 protein (p.Lys825Arg). This variant is present in population databases (rs753921188, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with SBF2-related conditions. ClinVar contains an entry for this variant (Variation ID: 306598). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt SBF2 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Benign
-0.086
T
BayesDel_noAF
Uncertain
-0.080
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Benign
0.18
T
Eigen
Uncertain
0.32
Eigen_PC
Uncertain
0.44
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Benign
0.070
D
MetaRNN
Uncertain
0.58
D
MetaSVM
Uncertain
-0.25
T
MutationAssessor
Benign
1.2
L
PhyloP100
8.0
PrimateAI
Uncertain
0.75
T
PROVEAN
Benign
-2.0
N
REVEL
Uncertain
0.39
Sift
Benign
0.39
T
Sift4G
Benign
0.25
T
Polyphen
0.72
P
Vest4
0.84
MutPred
0.29
Loss of methylation at K825 (P = 0.0096);
MVP
0.92
MPC
0.33
ClinPred
0.16
T
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.29
gMVP
0.46
Mutation Taster
=75/25
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.14
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs753921188; hg19: chr11-9875149; API