rs727503430

chr7-107704386-G-A

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_000441.2(SLC26A4):c.2089+1G>A variant causes a splice donor change. The variant allele was found at a frequency of 0.00000798 in 1,253,828 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000054 (0 hom.)
• Consequence: SLC26A4 NM_000441.2 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:10
• Conservation: PhyloP100: 7.13

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]

ACMG classification

Verdict is Pathogenic. Variant got 22 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 4.1, offset of 28, new splice context is: cctGTaaga. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 7-107704386-G-A is Pathogenic according to our data. Variant chr7-107704386-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 165263.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-107704386-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SLC26A4	NM_000441.2	c.2089+1G>A		splice_donor_variant		ENST00000644269.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SLC26A4	ENST00000644269.2	c.2089+1G>A		splice_donor_variant			NM_000441.2	P1
SLC26A4	ENST00000644846.1	c.745+2329G>A		intron_variant, NMD_transcript_variant
SLC26A4	ENST00000492030.2	n.376+1G>A		splice_donor_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152062 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000725

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

GnomAD3 exomes AF: 0.0000135 AC: 3 AN: 222764 Hom.: 0 AF XY: 0.00000836 AC XY: 1 AN XY: 119688

Gnomad AFR exome AF: 0.000139

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000106

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000545 AC: 6 AN: 1101766 Hom.: 0 Cov.: 15 AF XY: 0.00000355 AC XY: 2 AN XY: 562718

Gnomad4 AFR exome AF: 0.0000751

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: 0.00000380

Gnomad4 OTH exome AF: 0.0000208

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152062 Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3 AN XY: 74264

Gnomad4 AFR AF: 0.0000725

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: 0.0000952 Hom.: 0

Bravo AF: 0.0000340

ExAC AF: 0.00000832 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Pendred syndrome Pathogenic:4

Likely pathogenic, no assertion criteria provided	clinical testing	Counsyl	Feb 02, 2016	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Oct 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 15, 2022	Variant summary: SLC26A4 c.2089+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.3e-05 in 222764 control chromosomes (gnomAD). The variant, c.2089+1G>A, has been reported in the literature in homozygous and compound heterozygous state in individuals affected with hearing loss, with- or without the thyroid signs that are characteristic for Pendred Syndrome (e.g. Albert_2006, Ladsous_2014, Sheppard_2018). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014, and all laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -

Autosomal recessive nonsyndromic hearing loss 4 Pathogenic:3

Pathogenic, no assertion criteria provided	research	Division of Human Genetics, Children's Hospital of Philadelphia	Sep 25, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jun 07, 2023	- -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 05, 2024	This sequence change affects a donor splice site in intron 18 of the SLC26A4 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in SLC26A4 are known to be pathogenic (PMID: 16283880, 25394566, 26252218, 26445815). This variant is present in population databases (rs727503430, gnomAD 0.02%). Disruption of this splice site has been observed in individuals with Pendred syndrome (PMID: 2422447, 15355436). ClinVar contains an entry for this variant (Variation ID: 165263). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	May 03, 2017	The c.2089+1G>A variant in the SLC26A4 gene has been reported previously in the presence of another SLC26A4 variant, in individuals with Pendred syndrome, exhibiting sensorineural hearing loss, vestibular aqueductal enlargement and both with and without thyroid involvement (Blons et al., 2004; Banghova et al., 2008; Ladsous et al., 2014). This splice site variant destroys the canonical splice donor site in intron 18. It is predicted to cause abnormal gene splicing, either leading to an abnormal message that is subject to nonsense-mediated mRNA decay, or to an abnormal protein product if the message is used for protein translation. The c.2089+1G>A variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). We interpret c.2089+1G>A as a pathogenic variant. -

Rare genetic deafness Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Apr 11, 2014

The 2089+1G>A variant in SLC26A4 has been previously identified in two individua ls with Pendred syndrome and segregated with disease in an affected sibling of one of these individuals (Blons 2004, Banghova 2008). This variant was absent fr om large population studies. The variant occurs in the invariant region (+1/2) o f the 5? splice consensus sequence and is predicted to cause altered splicing le ading to an abnormal or absent protein. In summary, this variant meets our crite ria to be classified as pathogenic (http://pcpgm.partners.org/LMM). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.42
Cadd	Pathogenic	35
Dann	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	D;D;D;D
GERP RS		5.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.42		Position offset: 40
DS_DL_spliceai		0.99		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs727503430; hg19: chr7-107344831;