rs397516431

Positions:

• chr7-107675041-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000441.2(SLC26A4):​c.697G>C​(p.Val233Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000421 in 1,613,880 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 30)
  • Exomes 𝑓: 0.000042 (0 hom.)
• Consequence: SLC26A4 NM_000441.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:8
• Conservation: PhyloP100: 7.25

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a transmembrane_region Helical (size 20) in uniprot entity S26A4_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_000441.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.885

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SLC26A4	NM_000441.2	c.697G>C	p.Val233Leu	missense_variant	6/21	ENST00000644269.2	NP_000432.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SLC26A4	ENST00000644269.2	c.697G>C	p.Val233Leu	missense_variant	6/21		NM_000441.2	ENSP00000494017.1

Frequencies

GnomAD3 genomes AF: 0.0000395 AC: 6 AN: 152086 Hom.: 0 Cov.: 30

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000962

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: 0.000103 AC: 26 AN: 251476 Hom.: 0 AF XY: 0.0000956 AC XY: 13 AN XY: 135916

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00141

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: 0.0000424 AC: 62 AN: 1461794 Hom.: 0 Cov.: 31 AF XY: 0.0000358 AC XY: 26 AN XY: 727206

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00141

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000828

GnomAD4 genome AF: 0.0000395 AC: 6 AN: 152086 Hom.: 0 Cov.: 30 AF XY: 0.0000404 AC XY: 3 AN XY: 74298

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000962

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000491

ExAC AF: 0.0000247 AC: 3

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:8

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Dec 10, 2020	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 21, 2024	This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 233 of the SLC26A4 protein (p.Val233Leu). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with congenital hypothyroidism and/or deafness (PMID: 17443271, 25788563, 26886089, 28215547, 32459320, 34170635). 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: 43564). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SLC26A4 protein function with a positive predictive value of 80%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 08, 2024	In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 28215547, 35640668, 33159754, 34170635, 30245029, 33199029, 28576516, 34752165, 30235673, 37017887, 17443271, 33907123, 30579095, 29605365, 31581539, 32459320, 26886089) -

Pendred syndrome Uncertain:3

Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Nov 14, 2017	- -

Autosomal recessive nonsyndromic hearing loss 4 Pathogenic:1 Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -
Likely pathogenic, no assertion criteria provided	research	Precision Medicine Center, Zhengzhou University	-	- -

not specified Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 03, 2023	Variant summary: SLC26A4 c.697G>C (p.Val233Leu) 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 allele was found at a frequency of 0.0001 in 251476 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in SLC26A4 causing Pendred Syndrome (0.0001 vs 0.0035), allowing no conclusion about variant significance. c.697G>C has been reported in the literature as a compound heterozygous genotype in individuals affected with enlarged vestibular aqueduct (EVA) (example, Hu_2007, Tian_2021) as well as a non-informative genotype in settings of multigene panel testing for hearing loss, congenital hypothyroidism (CH) (example, Nishio_2015, Fan_2017, Chen_2022, Yamaguchi_2020). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (VUS, n=4; Likely pathogenic, n=1). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Mar 08, 2011	Variant classified as Uncertain Significance - Favor Pathogenic. The Val233Leu v ariant in SLC26A4 has been reported as a compound heterozygous variant with anot her pathogenic variant in a Chinese proband with hearing loss and enlarged vesti bular aqueduct (EVA) and was absent in 200 race matched control chromosomes (Hu, 2007). However, it was not reported whether this variant was in trans with the second SLC26A4 variant. Furthermore, computational analyses (biochemical amino a cid properties, homology, PolyPhen, SIFT, AlignGVGD) do not provide strong suppo rt for or against pathogenicity. In summary, the clinical significance of this v ariant cannot be determined with certainty at this time. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.40
BayesDel_addAF	Uncertain	0.093	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.65	D;D
Eigen	Uncertain	0.60
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	.;D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.89	D;D
MetaSVM	Uncertain	0.52	D
MutationAssessor	Benign	1.5	L;L
PrimateAI	Uncertain	0.71	T
PROVEAN	Uncertain	-2.5	D;.
REVEL	Pathogenic	0.78
Sift	Uncertain	0.0080	D;.
Sift4G	Uncertain	0.0090	D;.
Polyphen		0.99	D;D
Vest4		0.93
MutPred		0.89		Loss of catalytic residue at Q235 (P = 0.1485);Loss of catalytic residue at Q235 (P = 0.1485);
MVP		0.97
MPC		0.061
ClinPred		0.26	T
GERP RS		5.4
Varity_R		0.76
gMVP		0.89

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

Other links and lift over

dbSNP: rs397516431; hg19: chr7-107315486;