rs747026995

Positions:

• chr2-108010791-C-G
• chr2-108010791-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_021815.5(SLC5A7):​c.1673C>G​(p.Thr558Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,460,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: SLC5A7 NM_021815.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.79

Genes affected

SLC5A7 (HGNC:14025): (solute carrier family 5 member 7) This gene encodes a sodium ion- and chloride ion-dependent high-affinity transporter that mediates choline uptake for acetylcholine synthesis in cholinergic neurons. The protein transports choline from the extracellular space into presynaptic terminals for synthesis into acetylcholine. Increased choline uptake results from increased density of this protein in synaptosomal plasma membranes in response to depolarization of cholinergic terminals. Dysfunction of cholinergic signaling has been implicated in various disorders including depression, attention-deficit disorder, and schizophrenia. An allelic variant of this gene is associated with autosomal dominant distal hereditary motor neuronopathy type VIIA. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2015]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.21021253).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SLC5A7	NM_021815.5	c.1673C>G	p.Thr558Ser	missense_variant	9/9	ENST00000264047.3	NP_068587.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SLC5A7	ENST00000264047.3	c.1673C>G	p.Thr558Ser	missense_variant	9/9	1	NM_021815.5	ENSP00000264047	P1
SLC5A7	ENST00000409059.5	c.1673C>G	p.Thr558Ser	missense_variant	9/9	1		ENSP00000387346	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1460882 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726794

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neuronopathy, distal hereditary motor, type 7A;C4310694:Congenital myasthenic syndrome 20 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 24, 2023

This sequence change replaces threonine, which is neutral and polar, with serine, which is neutral and polar, at codon 558 of the SLC5A7 protein (p.Thr558Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SLC5A7-related conditions. ClinVar contains an entry for this variant (Variation ID: 450240). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant  is likely to be tolerated. 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 16, 2023

Has not been previously published as pathogenic or benign to our knowledge; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.078
BayesDel_addAF	Uncertain	0.084	D
BayesDel_noAF	Benign	-0.12
CADD	Benign	21
DANN	Uncertain	0.99
DEOGEN2	Benign	0.19	T;T
Eigen	Benign	0.16
Eigen_PC	Uncertain	0.33
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.74	.;T
M_CAP	Benign	0.038	D
MetaRNN	Benign	0.21	T;T
MetaSVM	Uncertain	0.27	D
MutationAssessor	Uncertain	2.3	M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-0.020	N;N
REVEL	Uncertain	0.40
Sift	Benign	0.32	T;T
Sift4G	Benign	0.23	T;T
Polyphen		0.017	B;B
Vest4		0.48
MutPred		0.12		Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);
MVP		0.89
MPC		0.036
ClinPred		0.69	D
GERP RS		6.0
Varity_R		0.15
gMVP		0.42

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: rs747026995; hg19: chr2-108627247;