17-6695837-G-T

Variant names:

• chr17-6695837-G-T
• rs138841868
• NM_177550.5:c.944C>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_177550.5(SLC13A5):​c.944C>A​(p.Ala315Glu) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,872 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A315T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SLC13A5 NM_177550.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.19
• Publications: 0 publications found

Genes affected

SLC13A5 (HGNC:23089): (solute carrier family 13 member 5) This gene encodes a protein belonging to the solute carrier family 13 group of proteins. This family member is a sodium-dependent citrate cotransporter that may regulate metabolic processes. Mutations in this gene cause early infantile epileptic encephalopathy 25. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2014]

SLC13A5 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 25

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• amelocerebrohypohidrotic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• pyridoxine-dependent epilepsy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC13A5	NM_177550.5	c.944C>A	p.Ala315Glu	missense_variant	Exon 7 of 12	ENST00000433363.7	NP_808218.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC13A5	ENST00000433363.7	c.944C>A	p.Ala315Glu	missense_variant	Exon 7 of 12	1	NM_177550.5	ENSP00000406220.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461872 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727236

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

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

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53400

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 25 Uncertain:1

Apr 25, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine with glutamic acid at codon 315 of the SLC13A5 protein (p.Ala315Glu). The alanine residue is moderately conserved and there is a moderate physicochemical difference between alanine and glutamic acid. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a SLC13A5-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may alter RNA splicing, but this prediction has not been confirmed by published transcriptional studies. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.57
BayesDel_addAF	Benign	-0.091	T
BayesDel_noAF	Benign	-0.37
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.31	T;.;.;.
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Benign	0.84	T;D;T;D
M_CAP	Benign	0.020	T
MetaRNN	Uncertain	0.67	D;D;D;D
MetaSVM	Benign	-1.2	T
MutationAssessor	Benign	1.7	L;.;.;L
PhyloP100		5.2
PrimateAI	Uncertain	0.50	T
PROVEAN	Uncertain	-4.2	D;D;D;.
REVEL	Benign	0.19
Sift	Uncertain	0.0030	D;D;D;.
Sift4G	Benign	0.21	T;T;T;T
Polyphen		1.0	D;.;.;.
Vest4		0.49
MutPred		0.48		Gain of solvent accessibility (P = 0.0789);.;.;Gain of solvent accessibility (P = 0.0789);
MVP		0.46
MPC		0.93
ClinPred		0.99	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.71
gMVP		0.89

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

Other links and lift over

dbSNP: rs138841868; hg19: chr17-6599156;