NM_004863.4:c.1226C>T

Variant summary

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

The NM_004863.4(SPTLC2):​c.1226C>T​(p.Thr409Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000018 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. T409K) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

SPTLC2
NM_004863.4 missense

Scores

9
5
4

Clinical Significance

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

Conservation

PhyloP100: 8.15

Publications

2 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 26 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004863.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SPTLC2
NM_004863.4
MANE Select
c.1226C>Tp.Thr409Met
missense
Exon 9 of 12NP_004854.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SPTLC2
ENST00000216484.7
TSL:1 MANE Select
c.1226C>Tp.Thr409Met
missense
Exon 9 of 12ENSP00000216484.2
SPTLC2
ENST00000554901.1
TSL:1
c.1034C>Tp.Thr345Met
missense
Exon 8 of 9ENSP00000452189.1
SPTLC2
ENST00000554365.1
TSL:2
n.551C>T
non_coding_transcript_exon
Exon 3 of 3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152198
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000796
AC:
2
AN:
251206
AF XY:
0.00000737
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:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000178
AC:
26
AN:
1461850
Hom.:
0
Cov.:
32
AF XY:
0.0000151
AC XY:
11
AN XY:
727222
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44720
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:
86244
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000225
AC:
25
AN:
1111990
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.438
Heterozygous variant carriers
0
2
3
5
6
8
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:
152198
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74370
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41444
American (AMR)
AF:
0.00
AC:
0
AN:
15274
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:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
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

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:
0.0000564
Hom.:
0
Bravo
AF:
0.0000340
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Nov 28, 2016
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

A variant of uncertain significance has been identified in the SPTLC2 gene. The T409M variant has been reported as a pathogenic variant; however no additional information was provided (Astudillo et al.; Duan et al., 2015). Functions studies suggested that the T409M variant does not appear to be associated with HSAN1 and that it may be a benign variant (Bode et al., 2016). It was not observed with any significant frequency in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project. The T409M variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. In silico analysis predicts this variant is probably damaging to the protein structure/function. However, this substitution occurs at a position that is not conserved. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant.

Neuropathy, hereditary sensory and autonomic, type 1C Uncertain:1
Mar 12, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 409 of the SPTLC2 protein (p.Thr409Met). This variant is present in population databases (rs368357970, gnomAD 0.004%). This missense change has been observed in individual(s) with amyotrophic lateral sclerosis (PMID: 36966328). ClinVar contains an entry for this variant (Variation ID: 373497). 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%. Experimental studies have shown that this missense change does not substantially affect SPTLC2 function (PMID: 26681808). 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 v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.15
BayesDel_addAF
Pathogenic
0.26
D
BayesDel_noAF
Pathogenic
0.24
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.94
D
Eigen
Pathogenic
0.81
Eigen_PC
Pathogenic
0.80
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.97
D
M_CAP
Uncertain
0.12
D
MetaRNN
Uncertain
0.73
D
MetaSVM
Pathogenic
0.83
D
MutationAssessor
Pathogenic
3.2
M
PhyloP100
8.1
PrimateAI
Benign
0.48
T
PROVEAN
Uncertain
-3.2
D
REVEL
Pathogenic
0.67
Sift
Benign
0.12
T
Sift4G
Benign
0.072
T
Polyphen
0.89
P
Vest4
0.66
MVP
0.76
MPC
0.76
ClinPred
0.82
D
GERP RS
5.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.6
Varity_R
0.10
gMVP
0.91
Mutation Taster
=50/50

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
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: rs368357970; hg19: chr14-78018516; API