7-107786883-G-T

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PVS1 PM2 PP3 PP5_Moderate

The NM_000111.3(SLC26A3):c.915C>A(p.Tyr305Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,914 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 Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. Y305Y) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SLC26A3 NM_000111.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 0.618

Genes affected

SLC26A3 (HGNC:3018): (solute carrier family 26 member 3) The protein encoded by this gene is a transmembrane glycoprotein that transports chloride ions across the cell membrane in exchange for bicarbonate ions. It is localized to the mucosa of the lower intestinal tract, particularly to the apical membrane of columnar epithelium and some goblet cells. The protein is essential for intestinal chloride absorption, and mutations in this gene have been associated with congenital chloride diarrhea. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Pathogenic. Variant got 13 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 7-107786883-G-T is Pathogenic according to our data. Variant chr7-107786883-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 56009.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr7-107786883-G-T is described in Lovd as [Likely_pathogenic]. Variant chr7-107786883-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SLC26A3	NM_000111.3	c.915C>A	p.Tyr305Ter	stop_gained	8/21	ENST00000340010.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SLC26A3	ENST00000340010.10	c.915C>A	p.Tyr305Ter	stop_gained	8/21	1	NM_000111.3	P1
SLC26A3	ENST00000468551.1	n.193C>A		non_coding_transcript_exon_variant	2/5	2
SLC26A3	ENST00000379083.7	c.*706C>A		3_prime_UTR_variant, NMD_transcript_variant	8/20	2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152158 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 1 AN: 1461756 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727190

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152158 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74330

Gnomad4 AFR AF: 0.00

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: 0.0000204 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital secretory diarrhea, chloride type Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

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

-

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 05, 2023

This sequence change creates a premature translational stop signal (p.Tyr305*) in the SLC26A3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in SLC26A3 are known to be pathogenic (PMID: 9718329, 21394828). 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 premature translational stop signal has been observed in individual(s) with congenital chloride diarrhea (PMID: 9554749). ClinVar contains an entry for this variant (Variation ID: 56009). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.59
Cadd	Pathogenic	35
Dann	Uncertain	1.0
Eigen	Uncertain	0.27
Eigen_PC	Benign	0.089
FATHMM_MKL	Benign	0.75	D
MutationTaster	Benign	1.0	A;A
Vest4		0.81
GERP RS		1.8

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.65		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.65		Position offset: 26

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

Publications

LitVar

Other links and lift over

dbSNP: rs386833490; hg19: chr7-107427328;