rs776829771

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BS1_Supporting

The NM_006415.4(SPTLC1):​c.428-1G>T variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,264 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

SPTLC1
NM_006415.4 splice_acceptor, intron

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.67
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BS1
Variant frequency is greater than expected in population eas. gnomad4_exome allele frequency = 0.00000274 (4/1461264) while in subpopulation EAS AF= 0.000101 (4/39622). AF 95% confidence interval is 0.0000335. There are 0 homozygotes in gnomad4_exome. There are 2 alleles in male gnomad4_exome subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SPTLC1NM_006415.4 linkc.428-1G>T splice_acceptor_variant, intron_variant Intron 5 of 14 ENST00000262554.7 NP_006406.1 O15269-1A0A024R277Q6NUL7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SPTLC1ENST00000262554.7 linkc.428-1G>T splice_acceptor_variant, intron_variant Intron 5 of 14 1 NM_006415.4 ENSP00000262554.2 O15269-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD3 exomes
AF:
0.00000800
AC:
2
AN:
249874
Hom.:
0
AF XY:
0.0000148
AC XY:
2
AN XY:
135106
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000110
Gnomad SAS 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:
0.00000274
AC:
4
AN:
1461264
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
726914
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.000101
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
33
ExAC
AF:
0.00000824
AC:
1

ClinVar

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

Submissions by phenotype

Hereditary sensory and autonomic neuropathy type 1 Uncertain:1
May 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change affects an acceptor splice site in intron 5 of the SPTLC1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), however the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in SPTLC1 cause disease. This variant is present in population databases (rs776829771, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with SPTLC1-related conditions. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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
BayesDel_addAF
Pathogenic
0.28
D
BayesDel_noAF
Pathogenic
0.38
CADD
Pathogenic
33
DANN
Uncertain
0.99
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.90
FATHMM_MKL
Pathogenic
1.0
D
GERP RS
4.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.91
SpliceAI score (max)
0.99
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.42
Position offset: -22
DS_AL_spliceai
0.99
Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs776829771; hg19: chr9-94830381; API