5-134607035-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PM5PP3_Moderate

The NM_016103.4(SAR1B):c.512G>C(p.Arg171Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,684 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R171Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SAR1B
NM_016103.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.91

Variant links:

Genes affected

SAR1B (HGNC:10535): (secretion associated Ras related GTPase 1B) The protein encoded by this gene is a small GTPase that acts as a homodimer. The encoded protein is activated by the guanine nucleotide exchange factor PREB and is involved in protein transport from the endoplasmic reticulum to the Golgi. This protein is part of the COPII coat complex. Defects in this gene are a cause of chylomicron retention disease (CMRD), also known as Anderson disease (ANDD). Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Mar 2010]

SAR1B links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1

In a chain GTP-binding protein SAR1b (size 197) in uniprot entity SAR1B_HUMAN there are 15 pathogenic changes around while only 1 benign (94%) in NM_016103.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr5-134607035-C-T is described in Lovd as [Pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.873

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
SAR1B	NM_016103.4 linkuse as main transcript	c.512G>C	p.Arg171Pro	missense_variant	7/7	ENST00000402673.7
SAR1B	NM_001033503.3 linkuse as main transcript	c.512G>C	p.Arg171Pro	missense_variant	8/8
SAR1B	XM_047417257.1 linkuse as main transcript	c.512G>C	p.Arg171Pro	missense_variant	7/7
SAR1B	XM_047417258.1 linkuse as main transcript	c.308G>C	p.Arg103Pro	missense_variant	5/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SAR1B	ENST00000402673.7 linkuse as main transcript	c.512G>C	p.Arg171Pro	missense_variant	7/7	1	NM_016103.4	P1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152068

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000966

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251334

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135822

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

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:

0.00000137

AC:

AN:

1461616

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727130

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

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

AF:

0.0000263

AC:

AN:

152068

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74264

show subpopulations

Gnomad4 AFR

AF:

0.0000966

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000189

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 06, 2023

The c.512G>C (p.R171P) alteration is located in coding exon 6 of the SAR1B gene. This alteration results from a G to C substitution at nucleotide position 512, causing the arginine (R) at amino acid position 171 to be replaced by a proline (P). This allele was reported in one heterozygous individual in population-based cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. This alteration is predicted to be deleterious by in silico analysis. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 16, 2022

This variant is present in population databases (no rsID available, gnomAD 0.006%). 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 1519644). This variant has not been reported in the literature in individuals affected with SAR1B-related conditions. This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 171 of the SAR1B protein (p.Arg171Pro). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.97

BayesDel_addAF

Pathogenic

0.28

BayesDel_noAF

Pathogenic

0.33

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Benign

0.41

T;.;.;T;.;T

Eigen

Pathogenic

0.98

Eigen_PC

Pathogenic

0.87

FATHMM_MKL

Pathogenic

0.99

M_CAP

Uncertain

0.18

MetaRNN

Pathogenic

0.87

D;D;D;D;D;D

MetaSVM

Uncertain

0.65

MutationAssessor

Pathogenic

4.2

H;.;.;H;.;.

MutationTaster

Benign

1.0

D;D;D;D;D

PrimateAI

Pathogenic

0.82

PROVEAN

Pathogenic

-5.9

D;D;D;D;D;D

REVEL

Pathogenic

0.74

Sift

Pathogenic

0.0

D;D;D;D;D;D

Sift4G

Pathogenic

0.0010

D;D;D;D;D;.

Polyphen

1.0

D;.;.;D;.;.

Vest4

0.82

MutPred

0.70

Gain of catalytic residue at R171 (P = 0.0075);.;.;Gain of catalytic residue at R171 (P = 0.0075);.;.;

MVP

0.93

MPC

0.81

ClinPred

1.0

GERP RS

4.9

Varity_R

0.98

gMVP

0.84

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.090

Details are displayed if max score is > 0.2

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over