chr9-92047678-T-C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_006415.4(SPTLC1):​c.919A>G​(p.Met307Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,118 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 (★★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SPTLC1
NM_006415.4 missense

Scores

6
11
2

Clinical Significance

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

Conservation

PhyloP100: 7.72

Publications

0 publications found
Variant links:
Genes affected
SPTLC1 (HGNC:11277): (serine palmitoyltransferase long chain base subunit 1) This gene encodes a member of the class-II pyridoxal-phosphate-dependent aminotransferase family. The encoded protein is the long chain base subunit 1 of serine palmitoyltransferase. Serine palmitoyltransferase converts L-serine and palmitoyl-CoA to 3-oxosphinganine with pyridoxal 5'-phosphate and is the key enzyme in sphingolipid biosynthesis. Mutations in this gene were identified in patients with hereditary sensory neuropathy type 1. Alternatively spliced variants encoding different isoforms have been identified. Pseudogenes of this gene have been defined on chromosomes 1, 6, 10, and 13. [provided by RefSeq, Jul 2013]
SPTLC1 Gene-Disease associations (from GenCC):
  • amyotrophic lateral sclerosis 27, juvenile
    Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • neuropathy, hereditary sensory and autonomic, type 1A
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • 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_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.953

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SPTLC1NM_006415.4 linkc.919A>G p.Met307Val missense_variant Exon 10 of 15 ENST00000262554.7 NP_006406.1 O15269-1A0A024R277Q6NUL7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SPTLC1ENST00000262554.7 linkc.919A>G p.Met307Val missense_variant Exon 10 of 15 1 NM_006415.4 ENSP00000262554.2 O15269-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461118
Hom.:
0
Cov.:
30
AF XY:
0.00000138
AC XY:
1
AN XY:
726920
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000299
AC:
1
AN:
33464
American (AMR)
AF:
0.00
AC:
0
AN:
44708
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:
86220
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53402
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111390
Other (OTH)
AF:
0.00
AC:
0
AN:
60372
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), 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
GnomAD4 genome
Cov.:
32

ClinVar

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

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Jul 16, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.919A>G (p.M307V) alteration is located in exon 10 (coding exon 10) of the SPTLC1 gene. This alteration results from a A to G substitution at nucleotide position 919, causing the methionine (M) at amino acid position 307 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hereditary sensory and autonomic neuropathy type 1 Uncertain:1
Aug 30, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 SPTLC1 protein function. ClinVar contains an entry for this variant (Variation ID: 456606). This variant has not been reported in the literature in individuals affected with SPTLC1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces methionine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 307 of the SPTLC1 protein (p.Met307Val). 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
Uncertain
0.37
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.27
CADD
Uncertain
24
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.87
D
Eigen
Uncertain
0.27
Eigen_PC
Uncertain
0.37
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.95
D
M_CAP
Uncertain
0.22
D
MetaRNN
Pathogenic
0.95
D
MetaSVM
Uncertain
0.47
D
MutationAssessor
Uncertain
2.3
M
PhyloP100
7.7
PrimateAI
Uncertain
0.68
T
PROVEAN
Benign
-2.3
N
REVEL
Pathogenic
0.80
Sift
Uncertain
0.011
D
Sift4G
Uncertain
0.018
D
Polyphen
0.13
B
Vest4
0.95
MutPred
0.83
Gain of sheet (P = 0.1945);
MVP
0.85
MPC
0.51
ClinPred
0.96
D
GERP RS
5.0
Varity_R
0.77
gMVP
0.95
Mutation Taster
=44/56
disease causing

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: rs1554706531; hg19: chr9-94809960; API