Genetic Variant SLC26A2:p.Gln135Lys (chr5-149978055-C-A) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_000112.4(SLC26A2):c.403C>A(p.Gln135Lys) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,613,120 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 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SLC26A2
NM_000112.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts P:1U:2

Conservation

PhyloP100: 6.13

Variant links:

Genes affected

SLC26A2 (HGNC:10994): (solute carrier family 26 member 2) The diastrophic dysplasia sulfate transporter is a transmembrane glycoprotein implicated in the pathogenesis of several human chondrodysplasias. It apparently is critical in cartilage for sulfation of proteoglycans and matrix organization. [provided by RefSeq, Jul 2008]

SLC26A2 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.923

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC26A2	NM_000112.4 link	c.403C>A	p.Gln135Lys	missense_variant	Exon 2 of 3	ENST00000286298.5	NP_000103.2	P50443
SLC26A2	XM_017009191.3 link	c.403C>A	p.Gln135Lys	missense_variant	Exon 2 of 4		XP_016864680.1	P50443

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SLC26A2	ENST00000286298.5 link	c.403C>A	p.Gln135Lys	missense_variant	Exon 2 of 3	1	NM_000112.4	ENSP00000286298.4	P50443
SLC26A2	ENST00000503336.1 link	c.76C>A	p.Gln26Lys	missense_variant	Exon 1 of 2	3		ENSP00000426053.1	H0YA38
SLC26A2	ENST00000690410.1 link	n.635C>A		non_coding_transcript_exon_variant	Exon 2 of 2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152126

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1460994

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726714

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152126

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74312

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Diastrophic dysplasia

Pathogenic:1

Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not specified

Uncertain:1

Jul 03, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: SLC26A2 c.403C>A (p.Gln135Lys) results in a conservative amino acid change located in the SLC26A/SulP transporter domain (IPR011547) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250866 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.403C>A has been reported in the literature in a family affected with Diastrophic dysplasia without pedigree information available for independent evaluation (Rossi_2001). This report does not provide unequivocal conclusions about association of the variant with Sulfate Transporter-Related Osteochondrodysplasia. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 11241838). One submitter has cited a clinical-significance assessment for this variant to ClinVar after 2014 and has classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Diastrophic dysplasia;C0265274:Achondrogenesis, type IB;C1847593:Multiple epiphyseal dysplasia type 4;C1850554:Atelosteogenesis type II

Uncertain:1

Sep 01, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine with lysine at codon 135 of the SLC26A2 protein (p.Gln135Lys). The glutamine residue is highly conserved and there is a small physicochemical difference between glutamine and lysine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with diastrophic dysplasia (PMID: 11241838). ClinVar contains an entry for this variant (Variation ID: 56023). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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

0.47

BayesDel_addAF

Pathogenic

0.41

BayesDel_noAF

Pathogenic

0.35

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.63

D;.

Eigen

Pathogenic

0.78

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.94

D;D

M_CAP

Benign

0.071

MetaRNN

Pathogenic

0.92

D;D

MetaSVM

Uncertain

0.79

MutationAssessor

Uncertain

2.3

M;.

PrimateAI

Uncertain

0.57

PROVEAN

Benign

-1.6

N;N

REVEL

Pathogenic

0.82

Sift

Uncertain

0.023

D;D

Sift4G

Uncertain

0.031

D;D

Polyphen

0.97

D;.

Vest4

0.89

MutPred

0.82

Gain of ubiquitination at Q135 (P = 0.0267);.;

MVP

0.99

MPC

0.34

ClinPred

0.84

GERP RS

5.7

Varity_R

0.85

gMVP

0.86

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

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