12-22201614-T-C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_003034.4(ST8SIA1):​c.1009A>G​(p.Ile337Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,904 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

ST8SIA1
NM_003034.4 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.13

Publications

0 publications found
Variant links:
Genes affected
ST8SIA1 (HGNC:10869): (ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 1) Gangliosides are membrane-bound glycosphingolipids containing sialic acid. Ganglioside GD3 is known to be important for cell adhesion and growth of cultured malignant cells. The protein encoded by this gene is a type II membrane protein that catalyzes the transfer of sialic acid from CMP-sialic acid to GM3 to produce gangliosides GD3 and GT3. The encoded protein may be found in the Golgi apparatus and is a member of glycosyltransferase family 29. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jan 2015]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.12647405).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ST8SIA1NM_003034.4 linkc.1009A>G p.Ile337Val missense_variant Exon 5 of 5 ENST00000396037.9 NP_003025.1 Q92185-1
ST8SIA1NM_001304450.2 linkc.580A>G p.Ile194Val missense_variant Exon 4 of 4 NP_001291379.1 Q92185

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ST8SIA1ENST00000396037.9 linkc.1009A>G p.Ile337Val missense_variant Exon 5 of 5 1 NM_003034.4 ENSP00000379353.3 Q92185-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152176
Hom.:
0
Cov.:
33
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000274
AC:
4
AN:
1461728
Hom.:
0
Cov.:
30
AF XY:
0.00000275
AC XY:
2
AN XY:
727176
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33462
American (AMR)
AF:
0.00
AC:
0
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5752
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1111926
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.513
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152176
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74338
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41448
American (AMR)
AF:
0.00
AC:
0
AN:
15268
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Apr 09, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1009A>G (p.I337V) alteration is located in exon 5 (coding exon 5) of the ST8SIA1 gene. This alteration results from a A to G substitution at nucleotide position 1009, causing the isoleucine (I) at amino acid position 337 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.080
BayesDel_addAF
Benign
-0.29
T
BayesDel_noAF
Benign
-0.65
CADD
Benign
13
DANN
Uncertain
0.99
DEOGEN2
Benign
0.11
T
Eigen
Benign
-0.34
Eigen_PC
Benign
-0.16
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.61
T
M_CAP
Benign
0.0053
T
MetaRNN
Benign
0.13
T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.90
L
PhyloP100
2.1
PrimateAI
Benign
0.36
T
PROVEAN
Benign
0.31
N
REVEL
Benign
0.020
Sift
Benign
0.097
T
Sift4G
Benign
0.10
T
Polyphen
0.0040
B
Vest4
0.038
MutPred
0.42
Gain of sheet (P = 0.1945);
MVP
0.38
MPC
0.36
ClinPred
0.33
T
GERP RS
3.4
Varity_R
0.050
gMVP
0.41
Mutation Taster
=77/23
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

Publications

Other links and lift over

dbSNP: rs1369264221; hg19: chr12-22354548; API