rs727505230

Variant names:

• chr7-107700181-T-C
• rs727505230
• NM_000441.2:c.1707+6T>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3 PP5

The NM_000441.2(SLC26A4):​c.1707+6T>C variant causes a splice region, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SLC26A4 NM_000441.2 splice_region, intron
• Scores: Splicing: ADA: 0.9886
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 4.73
• Publications: 0 publications found

Genes affected

SLC26A4 (HGNC:8818): (solute carrier family 26 member 4) Mutations in this gene are associated with Pendred syndrome, the most common form of syndromic deafness, an autosomal-recessive disease. It is highly homologous to the SLC26A3 gene; they have similar genomic structures and this gene is located 3' of the SLC26A3 gene. The encoded protein has homology to sulfate transporters. [provided by RefSeq, Jul 2008]

SLC26A4 Gene-Disease associations (from GenCC):

• autosomal recessive nonsyndromic hearing loss 4

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• Pendred syndrome

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

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• thyroid hypoplasia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

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

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant 7-107700181-T-C is Pathogenic according to our data. Variant chr7-107700181-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 179934.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC26A4	NM_000441.2	c.1707+6T>C		splice_region_variant, intron_variant	Intron 15 of 20	ENST00000644269.2	NP_000432.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC26A4	ENST00000644269.2	c.1707+6T>C		splice_region_variant, intron_variant	Intron 15 of 20		NM_000441.2	ENSP00000494017.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1254518 Hom.: 0 Cov.: 18 AF XY: 0.00 AC XY: 0 AN XY: 635176

African (AFR) AF: 0.00 AC: 0 AN: 29424

American (AMR) AF: 0.00 AC: 0 AN: 44440

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24866

East Asian (EAS) AF: 0.00 AC: 0 AN: 38700

South Asian (SAS) AF: 0.00 AC: 0 AN: 81970

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53246

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5328

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 922946

Other (OTH) AF: 0.00 AC: 0 AN: 53598

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Rare genetic deafness Pathogenic:1

Nov 05, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1707+6T>C variant in SLC26A4 was absent from large population studies, but has been identified by our laboratory in one individual with hearing loss and e nlarged vestibular aqueducts (EVA) who also carried a pathogenic variant on the other copy of SLC26A4. This variant is located in the 5' splice region. Computat ional tools do not suggest an impact to splicing, though this information is not predictive enough to rule out pathogenicity. However, the presence of this vari ant in combination with a reported pathogenic variant and in an individual with hearing loss and EVA, increases the likelihood that the c.1707+6T>C variant is p athogenic. In summary, although additional studies are required to fully establi sh its clinical significance, the c.1707+6T>C variant is likely pathogenic. -

not provided Uncertain:1

Jan 27, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 15 of the SLC26A4 gene. It does not directly change the encoded amino acid sequence of the SLC26A4 protein. It affects a nucleotide within the consensus splice site. This variant has been observed in individual(s) with deafness (Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 179934). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). 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_noAF	Benign	-0.29
CADD	Uncertain	23
DANN	Benign	0.95
PhyloP100		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.88
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

Other links and lift over

dbSNP: rs727505230; hg19: chr7-107340626;