rs1555381416

Positions:

• chr15-34257712-C-T

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_001365088.1(SLC12A6):​c.620G>A​(p.Arg207His) variant causes a missense 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. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R207C) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SLC12A6 NM_001365088.1 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 7.91

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 17 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr15-34257713-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 5331.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=1}.
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SLC12A6. . Gene score misZ 2.9593 (greater than the threshold 3.09). Trascript score misZ 3.1172 (greater than threshold 3.09). GenCC has associacion of gene with agenesis of the corpus callosum with peripheral neuropathy, Charcot-Marie-Tooth disease, axonal, IIa 2II.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.963
• PP5: Variant 15-34257712-C-T is Pathogenic according to our data. Variant chr15-34257712-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 521402.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-34257712-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SLC12A6	NM_001365088.1	c.620G>A	p.Arg207His	missense_variant	6/26	ENST00000354181.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SLC12A6	ENST00000354181.8	c.620G>A	p.Arg207His	missense_variant	6/26	1	NM_001365088.1	A1
	ENST00000559867.1	n.267C>T		non_coding_transcript_exon_variant	2/2	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 01, 2022	Published functional studies demonstrate a complete loss of function (Park et al., 2020); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 33323309, 31439721, 35733399) -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 02, 2022	For these reasons, this variant has been classified as Pathogenic. 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 SLC12A6 protein function. ClinVar contains an entry for this variant (Variation ID: 521402). This missense change has been observed in individual(s) with autosomal dominant Charcot-Marie-Tooth disease (PMID: 31439721, 33323309). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 207 of the SLC12A6 protein (p.Arg207His). -

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 05, 2021

The c.620G>A (p.R207H) alteration is located in exon 5 (coding exon 5) of the SLC12A6 gene. This alteration results from a G to A substitution at nucleotide position 620, causing the arginine (R) at amino acid position 207 to be replaced by a histidine (H). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This alteration was reported as de novo in two patients with muscle weakness, delayed motor development, and neuropathy (Park, 2020). An additional heterozygous patient was reported with similar clinical features (Shi, 2021). Another alteration at the same codon, p.R207C (c.619C>T), was reported homozygous in a patient with agenesis of the corpus callosum with peripheral neuropathy (Uyanik, 2006). This amino acid position is highly conserved in available vertebrate species. Based on internal structural analysis, this variant is anticipated to result in a significant decrease in structural stability and change (or disrupt) the ion transportation (Ambry internal data). A functional study showed KCC3-mediated K+ influx was absent in Xenopus oocytes injected with p.R270H mutant cotransporters, indicating a loss of protein function (Park, 2020). This alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, this alteration is classified as pathogenic. -

Charcot-Marie-Tooth disease, axonal, IIa 2II Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Oct 07, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.99	.;.;D;D;.;.;D;.;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	D;D;.;.;.;D;D;D;D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.2	.;.;H;H;.;.;H;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-4.6	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D;D;D;D
Polyphen		1.0	.;D;D;D;.;.;D;.;.
Vest4		0.95
MutPred		0.83		.;.;Loss of stability (P = 0.0792);Loss of stability (P = 0.0792);.;.;Loss of stability (P = 0.0792);.;.;
MVP		0.97
MPC		1.1
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.71
gMVP		0.95

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: rs1555381416; hg19: chr15-34549913; COSMIC: COSV51622808; COSMIC: COSV51622808;