5-149980602-CTTGTTG-CTTGTTGTTG

Variant names:

• chr5-149980602-C-CTTG
• rs121908077
• NM_000112.4:c.1020_1022dupTGT

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PM4_Supporting PP3

The NM_000112.4(SLC26A2):​c.1020_1022dupTGT​(p.Val341dup) variant causes a disruptive inframe insertion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,782 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. V341V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SLC26A2 NM_000112.4 disruptive_inframe_insertion
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.97
• Publications: 8 publications found

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 Gene-Disease associations (from GenCC):

• achondrogenesis type IB

  Inheritance: AR Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, G2P, ClinGen
• atelosteogenesis type II

  Inheritance: AR Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: Orphanet, ClinGen, Ambry Genetics
• diastrophic dysplasia

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics, Orphanet
• multiple epiphyseal dysplasia

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• multiple epiphyseal dysplasia type 4

  Inheritance: AR Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_000112.4. Strenght limited to Supporting due to length of the change: 1aa.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC26A2	NM_000112.4	c.1020_1022dupTGT	p.Val341dup	disruptive_inframe_insertion	Exon 3 of 3	ENST00000286298.5	NP_000103.2
SLC26A2	XM_017009191.3	c.1020_1022dupTGT	p.Val341dup	disruptive_inframe_insertion	Exon 3 of 4		XP_016864680.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC26A2	ENST00000286298.5	c.1020_1022dupTGT	p.Val341dup	disruptive_inframe_insertion	Exon 3 of 3	1	NM_000112.4	ENSP00000286298.4
SLC26A2	ENST00000503336.1	c.372+2262_372+2264dupTGT		intron_variant	Intron 1 of 1	3		ENSP00000426053.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251132 AF XY: 0.00000737

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461782 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727206

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53386

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111952

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000434 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Diastrophic dysplasia;C0265274:Achondrogenesis, type IB;C1847593:Multiple epiphyseal dysplasia type 4;C1850554:Atelosteogenesis type II Uncertain:1

Aug 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant, c.1020_1022dup, results in the insertion of 1 amino acid(s) of the SLC26A2 protein (p.Val341dup), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SLC26A2-related conditions. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -

Diastrophic dysplasia Uncertain:1

Apr 01, 2022

Laboratory of Inherited Metabolic Diseases, Research centre for medical genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.0

Splicing

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

Other links and lift over

dbSNP: rs121908077; hg19: chr5-149360165;