chr14-77552203-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PP3_ModerateBS1_SupportingBS2

The NM_004863.4(SPTLC2):c.1196G>A(p.Arg399Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000254 in 1,613,978 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: 𝑓 0.00014 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

SPTLC2
NM_004863.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.91

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

SPTLC2 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.93

BS1

Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.000138 (21/152162) while in subpopulation AMR AF = 0.000655 (10/15276). AF 95% confidence interval is 0.000354. There are 0 homozygotes in GnomAd4. There are 12 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAd4 at 21 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SPTLC2	NM_004863.4 link	c.1196G>A	p.Arg399Gln	missense_variant	Exon 9 of 12	ENST00000216484.7	NP_004854.1	O15270A0A024R6H1
SPTLC2	XM_011537384.3 link	c.1196G>A	p.Arg399Gln	missense_variant	Exon 9 of 10		XP_011535686.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SPTLC2	ENST00000216484.7 link	c.1196G>A	p.Arg399Gln	missense_variant	Exon 9 of 12	1	NM_004863.4	ENSP00000216484.2		O15270

Frequencies

GnomAD3 genomes

AF:

0.000138

AC:

AN:

152162

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000217

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000279

AC:

AN:

251164

AF XY:

0.0000295

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000137

AC:

AN:

1461816

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727200

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33480

American (AMR)

AF:

0.0000894

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39690

South Asian (SAS)

AF:

0.00

AC:

AN:

86238

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53408

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000719

AC:

AN:

1111982

Other (OTH)

AF:

0.0000497

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.460

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.000138

AC:

AN:

152162

Hom.:

Cov.:

AF XY:

0.000161

AC XY:

AN XY:

74320

show subpopulations

African (AFR)

AF:

0.000217

AC:

AN:

41432

American (AMR)

AF:

0.000655

AC:

AN:

15276

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.000193

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.506

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.0000827

Hom.:

Bravo

AF:

0.000317

ESP6500AA

AF:

0.000681

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000494

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

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

May 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 399 of the SPTLC2 protein (p.Arg399Gln). This variant is present in population databases (rs143757018, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with SPTLC2-related conditions. ClinVar contains an entry for this variant (Variation ID: 471487). 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

Apr 05, 2022

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R399Q variant (also known as c.1196G>A), located in coding exon 9 of the SPTLC2 gene, results from a G to A substitution at nucleotide position 1196. The arginine at codon 399 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. 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

0.15

BayesDel_addAF

Pathogenic

0.35

BayesDel_noAF

Pathogenic

0.44

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.93

Eigen

Pathogenic

0.98

Eigen_PC

Pathogenic

0.90

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.90

M_CAP

Pathogenic

0.31

MetaRNN

Pathogenic

0.93

MetaSVM

Pathogenic

0.99

MutationAssessor

Pathogenic

3.1

PhyloP100

7.9

PrimateAI

Uncertain

0.69

PROVEAN

Uncertain

-3.6

REVEL

Pathogenic

0.81

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0040

Polyphen

1.0

Vest4

0.90

MVP

0.89

MPC

1.4

ClinPred

0.97

GERP RS

5.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.73

gMVP

0.92

Mutation Taster

=61/39

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.080

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over