20-46035852-C-T

Variant names:

• chr20-46035852-C-T
• rs3848724
• NM_020708.5:c.355C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_020708.5(SLC12A5):​c.355C>T​(p.Arg119Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,782 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R119Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SLC12A5 NM_020708.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.61
• Publications: 0 publications found

Genes affected

SLC12A5 (HGNC:13818): (solute carrier family 12 member 5) K-Cl cotransporters are proteins that lower intracellular chloride concentrations below the electrochemical equilibrium potential. The protein encoded by this gene is an integral membrane K-Cl cotransporter that can function in either a net efflux or influx pathway, depending on the chemical concentration gradients of potassium and chloride. The encoded protein can act as a homomultimer, or as a heteromultimer with other K-Cl cotransporters, to maintain chloride homeostasis in neurons. Alternative splicing results in two transcript variants encoding different isoforms. [provided by RefSeq, Sep 2008]

SLC12A5 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 34

  Inheritance: AR Classification: STRONG, MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Illumina, Ambry Genetics
• epilepsy of infancy with migrating focal seizures

  Inheritance: AR Classification: STRONG Submitted by: G2P
• malignant migrating partial seizures of infancy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• epilepsy, idiopathic generalized, susceptibility to, 14

  Inheritance: AD Classification: LIMITED, NO_KNOWN Submitted by: Illumina, Ambry Genetics
• genetic developmental and epileptic encephalopathy

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.957

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC12A5	NM_020708.5	c.355C>T	p.Arg119Trp	missense_variant	Exon 4 of 26	ENST00000243964.7	NP_065759.1
SLC12A5	NM_001134771.2	c.424C>T	p.Arg142Trp	missense_variant	Exon 4 of 26		NP_001128243.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC12A5	ENST00000243964.7	c.355C>T	p.Arg119Trp	missense_variant	Exon 4 of 26	1	NM_020708.5	ENSP00000243964.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461782 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727202

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111954

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Developmental and epileptic encephalopathy, 34 Uncertain:1

Jul 25, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 119 of the SLC12A5 protein (p.Arg119Trp). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SLC12A5-related conditions. ClinVar contains an entry for this variant (Variation ID: 1467419). 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 SLC12A5 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Movement disorder Uncertain:1

Jan 11, 2024

Unidad de Genómica Garrahan, Hospital de Pediatría Garrahan

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.96	D;D;.;D;D;.;.
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Pathogenic	1.0	D;D;D;D;D;D;D
M_CAP	Pathogenic	0.58	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.5	H;.;.;.;.;.;.
PhyloP100		1.6
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-7.0	D;.;.;.;.;.;D
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D;.;.;.;.;.;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D
Polyphen		1.0	D;.;.;.;.;.;D
Vest4		0.96
MutPred		0.79		Gain of helix (P = 0.0854);.;.;.;.;.;.;
MVP		0.99
MPC		2.1
ClinPred		1.0	D
GERP RS		2.5
Varity_R		0.91
gMVP		0.99
Mutation Taster		=39/61	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs3848724; hg19: chr20-44664491;