rs1555380998

Positions:

• chr15-34256227-A-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001365088.1(SLC12A6):​c.745+2T>A variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SLC12A6 NM_001365088.1 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 9.17

Genes affected

SLC12A6 (HGNC:10914): (solute carrier family 12 member 6) This gene is a member of the K-Cl cotransporter (KCC) family. K-Cl cotransporters are integral membrane proteins that lower intracellular chloride concentrations below the electrochemical equilibrium potential. The proteins encoded by this gene are activated by cell swelling induced by hypotonic conditions. Alternate splicing results in multiple transcript variants encoding different isoforms. Mutations in this gene are associated with agenesis of the corpus callosum with peripheral neuropathy. [provided by RefSeq, Jul 2008]

(HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 4.1, offset of 4, new splice context is: ataGTaggt. 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
• PP5: Variant 15-34256227-A-T is Pathogenic according to our data. Variant chr15-34256227-A-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 551233.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-34256227-A-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SLC12A6	NM_001365088.1	c.745+2T>A		splice_donor_variant		ENST00000354181.8	NP_001352017.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SLC12A6	ENST00000354181.8	c.745+2T>A		splice_donor_variant		1	NM_001365088.1	ENSP00000346112	A1
	ENST00000559867.1	n.126+816A>T		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 26

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Agenesis of the corpus callosum with peripheral neuropathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Counsyl

Apr 03, 2017

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 25, 2022

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. ClinVar contains an entry for this variant (Variation ID: 551233). Disruption of this splice site has been observed in individual(s) with agenesis of the corpus callosum with peripheral neuropathy (PMID: 26392352, 27717089). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 6 of the SLC12A6 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 SLC12A6 are known to be pathogenic (PMID: 12368912, 16606917). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	34
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
GERP RS		5.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.44		Position offset: -12
DS_DL_spliceai		0.99		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555380998; hg19: chr15-34548428;