rs771681797

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_004733.4(SLC33A1):​c.1037C>T​(p.Ala346Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,584 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. A346S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

SLC33A1
NM_004733.4 missense

Scores

9
9
1

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.86

Publications

0 publications found
Variant links:
Genes affected
SLC33A1 (HGNC:95): (solute carrier family 33 member 1) The protein encoded by this gene is required for the formation of O-acetylated (Ac) gangliosides. The encoded protein is predicted to contain 6 to 10 transmembrane domains, and a leucine zipper motif in transmembrane domain III. Defects in this gene have been reported to cause spastic paraplegia autosomal dominant type 42 (SPG42) in one Chinese family, but not in similar patients of European descent. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2010]
SLC33A1 Gene-Disease associations (from GenCC):
  • Huppke-Brendel syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)
  • hereditary spastic paraplegia 42
    Inheritance: AD Classification: SUPPORTIVE, LIMITED Submitted by: Illumina, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PP3
MetaRNN computational evidence supports a deleterious effect, 0.863

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SLC33A1NM_004733.4 linkc.1037C>T p.Ala346Val missense_variant Exon 3 of 6 ENST00000643144.2 NP_004724.1 O00400

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SLC33A1ENST00000643144.2 linkc.1037C>T p.Ala346Val missense_variant Exon 3 of 6 NM_004733.4 ENSP00000496241.1 O00400
ENSG00000284952ENST00000643876.1 linkn.*359C>T non_coding_transcript_exon_variant Exon 3 of 10 ENSP00000495323.1 A0A2R8Y6H1
ENSG00000284952ENST00000643876.1 linkn.*359C>T 3_prime_UTR_variant Exon 3 of 10 ENSP00000495323.1 A0A2R8Y6H1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152180
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251360
AF XY:
0.0000221
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:
0.00
Gnomad NFE exome
AF:
0.0000264
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000616
AC:
9
AN:
1461404
Hom.:
0
Cov.:
32
AF XY:
0.00000825
AC XY:
6
AN XY:
727030
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39666
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86242
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53390
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00000810
AC:
9
AN:
1111652
Other (OTH)
AF:
0.00
AC:
0
AN:
60370
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.508
Heterozygous variant carriers
0
1
2
3
4
5
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:
152180
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74352
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.0000312
Hom.:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

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

Submissions by phenotype

Spastic paraplegia Uncertain:1
May 07, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature in individuals with SLC33A1-related disease. 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant is present in population databases (rs771681797, ExAC 0.002%). This sequence change replaces alanine with valine at codon 346 of the SLC33A1 protein (p.Ala346Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.81
BayesDel_addAF
Pathogenic
0.37
D
BayesDel_noAF
Pathogenic
0.36
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.79
D;D;D
Eigen
Pathogenic
0.97
Eigen_PC
Pathogenic
0.97
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.93
.;.;D
M_CAP
Uncertain
0.13
D
MetaRNN
Pathogenic
0.86
D;D;D
MetaSVM
Uncertain
0.44
D
MutationAssessor
Uncertain
2.5
M;M;M
PhyloP100
9.9
PrimateAI
Uncertain
0.79
T
PROVEAN
Uncertain
-3.6
D;.;D
REVEL
Pathogenic
0.76
Sift
Uncertain
0.0030
D;.;D
Sift4G
Uncertain
0.016
D;.;D
Polyphen
0.99
D;D;D
Vest4
0.97
MutPred
0.55
Loss of glycosylation at K342 (P = 0.0441);Loss of glycosylation at K342 (P = 0.0441);Loss of glycosylation at K342 (P = 0.0441);
MVP
0.96
MPC
1.1
ClinPred
0.91
D
GERP RS
6.0
Varity_R
0.61
gMVP
0.96
Mutation Taster
=27/73
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs771681797; hg19: chr3-155551757; API