chr3-11033739-G-C

Variant names:

• chr3-11033739-G-C
• rs34969656
• NM_003042.4:c.1527G>C

Variant summary

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

The NM_003042.4(SLC6A1):​c.1527G>C​(p.Ala509Ala) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000275 in 1,453,508 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. A509A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: SLC6A1 NM_003042.4 splice_region, synonymous
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.42
• Publications: 3 publications found

Genes affected

SLC6A1 (HGNC:11042): (solute carrier family 6 member 1) The protein encoded by this gene is a gamma-aminobutyric acid (GABA) transporter that localizes to the plasma membrane. The encoded protein removes GABA from the synaptic cleft, restoring it to presynaptic terminals. [provided by RefSeq, Jan 2017]

SLC6A1 Gene-Disease associations (from GenCC):

• epilepsy with myoclonic atonic seizures

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Illumina, G2P, Labcorp Genetics (formerly Invitae)
• myoclonic-astatic epilepsy

  Inheritance: Unknown Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

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

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC6A1	NM_003042.4	c.1527G>C	p.Ala509Ala	splice_region_variant, synonymous_variant	Exon 14 of 16	ENST00000287766.10	NP_003033.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC6A1	ENST00000287766.10	c.1527G>C	p.Ala509Ala	splice_region_variant, synonymous_variant	Exon 14 of 16	1	NM_003042.4	ENSP00000287766.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250770 AF XY: 0.00000738

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000275 AC: 4 AN: 1453508 Hom.: 0 Cov.: 27 AF XY: 0.00000415 AC XY: 3 AN XY: 723608

African (AFR) AF: 0.00 AC: 0 AN: 33322

American (AMR) AF: 0.00 AC: 0 AN: 44676

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26052

East Asian (EAS) AF: 0.00 AC: 0 AN: 39658

South Asian (SAS) AF: 0.00 AC: 0 AN: 85852

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53370

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5738

European-Non Finnish (NFE) AF: 0.00000362 AC: 4 AN: 1104722

Other (OTH) AF: 0.00 AC: 0 AN: 60118

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Epilepsy with myoclonic atonic seizures Uncertain:1

Dec 30, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects codon 509 of the SLC6A1 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the SLC6A1 protein. This variant also falls at the last nucleotide of exon 14, which is part of the consensus splice site for this exon. This variant is present in population databases (rs34969656, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with SLC6A1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1800622). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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

May 17, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports a deleterious effect on splicing; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
CADD	Benign	19
DANN	Benign	0.89
PhyloP100		2.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.73		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.73		Position offset: 0

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

Other links and lift over

dbSNP: rs34969656; hg19: chr3-11075425;