About SLC12A3
No gene-level summary was recorded for this case.
No variant summary was recorded for this case.
Five-step scale from benign to pathogenic. This variant is likely pathogenic. Select a step to read what it means.
Likely pathogenic.A likely pathogenic classification under the recorded framework.
Gene-level background from the recorded interpretation.
Words with a dotted underline have a short definition. Hover or tap them.No gene-level summary was recorded for this case.
The recorded framework is Not recorded. The criteria and strengths shown below come from the saved assessment; this page does not recalculate the classification.
The applied criteria and their strengths are shown as assessed under the stated framework.
Well-established functional studies across three independent publications demonstrate that c.1670-191C>T creates a novel donor splice site in intron 13, resulting in 238-bp cryptic exon inclusion, a premature termination codon, and loss of functional NCC protein. RT-PCR from patient leukocytes and urinary sediments (PMID:19668106), RNA and immunohistochemistry analyses in 19 patients showing marked attenuation of NCC expression in the distal convoluted tubule (PMID:21051746), and midigene splice assays (PMID:36302598) all consistently confirm the damaging splicing effect.
The variant has been observed in at least 27 unrelated probands with Gitelman syndrome across multiple independent studies (19 patients in PMID:21051746, 7 patients in PMID:36302598, 1 homozygous patient in PMID:32860008), while being extremely rare in population databases (gnomAD v4.1 AF = 0.0013%). The prevalence in affected individuals is substantially enriched compared to general population controls.
Variant is absent or at extremely low frequency in large population cohorts. gnomAD v2.1: 1/31,384 alleles (AF = 0.00319%); gnomAD v4.1: 2/152,332 alleles (AF = 0.00131%); gnomAD-Canada: absent. All allele frequencies are well below the 0.1% PM2 threshold. No homozygotes observed in population databases.
SpliceAI predicts a deleterious splicing impact with a maximum delta score of 0.72, consistent with creation of a novel splice site. The in silico prediction is corroborated by functional evidence (PS3).
The variant has been identified in multiple unrelated patients with Gitelman syndrome, a well-characterized disorder with SLC12A3 as the primary genetic etiology. The clinical phenotype (hypokalemia, hypomagnesemia, metabolic alkalosis, hypocalciuria) is highly specific for this gene.
No benign criterion marked as applied in the recorded assessment.
gene-specific framework lacked a usable explicit final combination framework, so generic ACMG/AMP 2015 final-combination rules were applied as fallback; applied criteria: PS3 strong, PS4 moderate, PM2 supporting, PP3 supporting, PP4 supporting; combination = 1 strong + 1 moderate + 3 supporting, which maps to Likely Pathogenic.
Evidence summaries and captured source records, where available. Missing entries should not be interpreted as negative findings.
gnomAD v4.1: 2 / 152,332 alleles. Recorded AF 1.31292e-05. Recorded homozygote count 0.
This variant is present in gnomAD v2.1 (AF= 3.18634e-05; MAF= 0.00319%, 1/31384 alleles, homozygotes = 0) and has highest observed frequency in the East Asian population (AF= 0.000641026; MAF= 0.06410%, 1/1560 alleles, homozygotes = 0).
This variant is present in gnomAD-Canada v1.0 (AF= 0.00016291951775822744, 3/18414 alleles, homozygotes = 0).
Recorded SpliceAI maximum delta score: 0.720. Refer to the recorded PP3/BP4 rationale for interpretation.
13 Pathogenic.
No standalone functional evidence summary is recorded in evidence_summary.functional.
This variant has not previously been reported in somatic cancers (COSMIC).
ACMG/AMP criteria under Not recorded, with the data and sources behind each one.
26 criteria with recorded statuses: 5 met · 7 not met · 6 not assessed · 8 not applicable. Open any row for the full reasoning, the rule and the evidence behind it.
c.1670-191C>T is a deep intronic substitution in intron 13 of SLC12A3 that creates a novel donor splice site, leading to 238-bp cryptic exon inclusion and a premature termination codon, as demonstrated by RT-PCR from patient leukocytes and urine sediments.
RNA and immunohistochemistry analyses in 19 patients from 14 families confirmed cryptic exon inclusion and marked attenuation of NCC expression in the distal convoluted tubule, establishing the variant as a recurrent pathogenic deep intronic mutation in Gitelman syndrome.
Independent midigene splice assays confirmed aberrant splicing with activation of a cryptic splice donor site, further validating the damaging molecular mechanism.
The variant is extremely rare in population databases: gnomAD v2.1 allele frequency is 0.0032% (1/31,384 alleles) and gnomAD v4.1 allele frequency is 0.0013% (2/152,332 alleles), with no homozygotes observed.
At least 27 unrelated probands with biochemically confirmed Gitelman syndrome have been reported to carry this variant across multiple independent studies, consistent with a substantial enrichment in affected individuals compared to the general population.
SpliceAI in silico prediction supports a deleterious splicing effect with a maximum delta score of 0.72, consistent with the experimentally confirmed cryptic splice site activation.
Gitelman syndrome is a well-characterized autosomal recessive salt-losing tubulopathy for which SLC12A3 is the established disease gene, and the patients' clinical phenotypes (hypokalemia, hypomagnesemia, metabolic alkalosis, hypocalciuria) are highly specific.
Applying the generic ACMG/AMP 2015 combination rules: PS3 (strong), PS4 (moderate), PM2 (supporting), PP3 (supporting), and PP4 (supporting) yields a classification of Pathogenic (1 strong + 1 moderate + 3 supporting).
No criteria match.
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Every interpreted variant in SLC12A3, mapped onto the exon structure of NM_001126108.2. Select a row to find it on the plot.
| Protein | Location | Classification | Link |
|---|
| South Asian1 / 4,822 | 0.00021 |
| East Asian1 / 5,184 | 0.00019 |
| East Asian1 / 1,560 | 0.00064 |
This variant is present in gnomAD v4.1 (AF= 1.31292e-05; MAF= 0.00131%, 2/152332 alleles, homozygotes = 0) and has highest observed frequency in the South Asian population (AF= 0.000207383; MAF= 0.02074%, 1/4822 alleles, homozygotes = 0).
This variant is present in gnomAD v2.1 (AF= 3.18634e-05; MAF= 0.00319%, 1/31384 alleles, homozygotes = 0) and has highest observed frequency in the East Asian population (AF= 0.000641026; MAF= 0.06410%, 1/1560 alleles, homozygotes = 0).
This variant is present in gnomAD-Canada v1.0 (AF= 0.00016291951775822744, 3/18414 alleles, homozygotes = 0).
No further detail was recorded.
SpliceAI predicts possible splice impact for this variant (max delta score = 0.72).
7 paper records listed. 4 cited in the classification.
The genomic DNA analysis of intron 13 revealed a single-base substitution (c.1670–191C→T) that creates a new donor splice site within the intron resulting in the inclusion of a novel cryptic exon in mRNA.
Location Abstract; Results paragraphs 1-2; Figures 1C, 2, 4; Discussion paragraphs 1-2
Context RT-PCR from patient blood leukocytes and urine sediment RNA; subcloning and Sanger sequencing; SLC12A3 transcript analysis (exons 13-15)
We identified nine Taiwan aboriginal patients carrying c.1670–191C→T mutations in intron 13 and 10 nonaboriginal patients with c.2548+253C→T mutations in intron 21.
Location Abstract; Results (Identification of Deep Intronic Mutations, Functional Significance); Table 1; Table 3; Figures 2, 4
Context RT-PCR from leukocyte RNA; immunohistochemistry of NCC in human renal biopsy tissue; haplotype analysis with microsatellite markers flanking SLC12A3
NM_000339.2 (SLC12A3):c.1670–191C>T NC_000016.9:g.56917770C>T Hom P Gitelman syndrome
Location Supplementary material (variant table); Results
Context Clinical genome sequencing diagnostic cohort (CENTOGENE)
Midigene splice assays of the previously known c.1670-191C>T variant and intronic candidate variants demonstrated aberrant splicing.
Location Results (Midigene Splice Assays, Table 1); Discussion
Context Midigene splice assays in HEK293T cells; long-read sequencing (Pacific Biosciences)
Screenshots represent source records captured during evidence collection. Select one to view the recorded source content.
The evidence statements recorded by the interpretation pipeline. They have not been reinterpreted by the page.
This variant is present in gnomAD v4.1 (AF= 1.31292e-05; MAF= 0.00131%, 2/152332 alleles, homozygotes = 0) and has highest observed frequency in the South Asian population (AF= 0.000207383; MAF= 0.02074%, 1/4822 alleles, homozygotes = 0).
This variant is present in gnomAD v2.1 (AF= 3.18634e-05; MAF= 0.00319%, 1/31384 alleles, homozygotes = 0) and has highest observed frequency in the East Asian population (AF= 0.000641026; MAF= 0.06410%, 1/1560 alleles, homozygotes = 0).
This variant is present in gnomAD-Canada v1.0 (AF= 0.00016291951775822744, 3/18414 alleles, homozygotes = 0).
This variant has been reported in ClinVar as Pathogenic (13 clinical laboratories). (ClinVarID = 665361)
SpliceAI predicts possible splice impact for this variant (max delta score = 0.72).
This variant has not previously been reported in somatic cancers (COSMIC).