NM_004863.4:c.994G>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BS2

The NM_004863.4(SPTLC2):​c.994G>T​(p.Ala332Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000496 in 1,614,012 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. A332A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

SPTLC2
NM_004863.4 missense

Scores

1
12
6

Clinical Significance

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

Conservation

PhyloP100: 6.00

Publications

1 publications found
Variant links:
Genes affected
SPTLC2 (HGNC:11278): (serine palmitoyltransferase long chain base subunit 2) This gene encodes a long chain base subunit of serine palmitoyltransferase. Serine palmitoyltransferase, which consists of two different subunits, is the key enzyme in sphingolipid biosynthesis. It catalyzes the pyridoxal-5-prime-phosphate-dependent condensation of L-serine and palmitoyl-CoA to 3-oxosphinganine. Mutations in this gene were identified in patients with hereditary sensory neuropathy type I. [provided by RefSeq, Mar 2011]
SPTLC2 Gene-Disease associations (from GenCC):
  • neuropathy, hereditary sensory and autonomic, type 1C
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Ambry Genetics
  • hereditary sensory and autonomic neuropathy type 1
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BS2
High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SPTLC2NM_004863.4 linkc.994G>T p.Ala332Ser missense_variant Exon 8 of 12 ENST00000216484.7 NP_004854.1
SPTLC2XM_011537384.3 linkc.994G>T p.Ala332Ser missense_variant Exon 8 of 10 XP_011535686.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SPTLC2ENST00000216484.7 linkc.994G>T p.Ala332Ser missense_variant Exon 8 of 12 1 NM_004863.4 ENSP00000216484.2

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152122
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000197
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:
251424
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000342
AC:
5
AN:
1461890
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112012
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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:
0.0000197
AC:
3
AN:
152122
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74312
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41418
American (AMR)
AF:
0.000197
AC:
3
AN:
15264
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:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.542
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Neuropathy, hereditary sensory and autonomic, type 1C Uncertain:1
Jul 06, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 332 of the SPTLC2 protein (p.Ala332Ser). This variant is present in population databases (rs767978353, gnomAD 0.01%). This missense change has been observed in individual(s) with clinical features of SPTLC2-related conditions (PMID: 31692161). ClinVar contains an entry for this variant (Variation ID: 471495). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SPTLC2 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. -

Inborn genetic diseases Uncertain:1
May 04, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A332S variant (also known as c.994G>T), located in coding exon 8 of the SPTLC2 gene, results from a G to T substitution at nucleotide position 994. The alanine at codon 332 is replaced by serine, an amino acid with similar properties. This variant was detected in an individual with adult-onset spasticity; however, clinical details were limited (Ngo KJ et al. Hum Mutat, 2020 02;41:487-501). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.097
BayesDel_addAF
Uncertain
0.10
D
BayesDel_noAF
Uncertain
0.11
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.59
D
Eigen
Uncertain
0.52
Eigen_PC
Uncertain
0.57
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.93
D
M_CAP
Uncertain
0.098
D
MetaRNN
Uncertain
0.45
T
MetaSVM
Benign
-0.35
T
MutationAssessor
Uncertain
2.6
M
PhyloP100
6.0
PrimateAI
Uncertain
0.69
T
PROVEAN
Benign
-1.7
N
REVEL
Uncertain
0.61
Sift
Benign
0.081
T
Sift4G
Benign
0.22
T
Polyphen
0.49
P
Vest4
0.48
MutPred
0.42
Gain of catalytic residue at L327 (P = 0.0061);
MVP
0.58
MPC
0.90
ClinPred
0.60
D
GERP RS
4.9
Varity_R
0.33
gMVP
0.54
Mutation Taster
=72/28
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: rs767978353; hg19: chr14-78021825; API