X-153688599-G-T

Position:

• chrX-153688599-G-T

Variant summary

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

The NM_005629.4(SLC6A8):​c.25G>T​(p.Gly9Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000105 in 950,416 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a benign 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. G9V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 20)
  • Exomes 𝑓: 0.0000011 (0 hom. 0 hem.)
• Consequence: SLC6A8 NM_005629.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.895

Genes affected

SLC6A8 (HGNC:11055): (solute carrier family 6 member 8) The protein encoded by this gene is a plasma membrane protein whose function is to transport creatine into and out of cells. Defects in this gene can result in X-linked creatine deficiency syndrome. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2008]

PNCK (HGNC:13415): (pregnancy up-regulated nonubiquitous CaM kinase) PNCK is a member of the calcium/calmodulin-dependent protein kinase family of protein serine/threonine kinases (see CAMK1; MIM 604998) (Gardner et al., 2000 [PubMed 10673339]).[supplied by OMIM, Mar 2008]

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=0.17451563).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SLC6A8	NM_005629.4	c.25G>T	p.Gly9Cys	missense_variant	1/13	ENST00000253122.10
SLC6A8	NM_001142805.2	c.25G>T	p.Gly9Cys	missense_variant	1/13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SLC6A8	ENST00000253122.10	c.25G>T	p.Gly9Cys	missense_variant	1/13	1	NM_005629.4	P1
PNCK	ENST00000458354.5	c.-3+216C>A		intron_variant		3
PNCK	ENST00000480693.1	n.64+216C>A		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 20

GnomAD4 exome AF: 0.00000105 AC: 1 AN: 950416 Hom.: 0 Cov.: 25 AF XY: 0.00 AC XY: 0 AN XY: 301832

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: 0.00000131

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 20

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Creatine transporter deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 04, 2022

This sequence change replaces glycine, which is neutral and non-polar, with cysteine, which is neutral and slightly polar, at codon 9 of the SLC6A8 protein (p.Gly9Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SLC6A8-related conditions. ClinVar contains an entry for this variant (Variation ID: 934136). 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 not expected to disrupt SLC6A8 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Benign	-0.53
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.13	T
FATHMM_MKL	Benign	0.46	N
LIST_S2	Benign	0.62	T
M_CAP	Pathogenic	0.97	D
MetaRNN	Benign	0.17	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.0	N
MutationTaster	Benign	0.70	N
PrimateAI	Pathogenic	0.89	D
PROVEAN	Benign	-0.16	N
REVEL	Benign	0.096
Sift	Benign	0.14	T
Sift4G	Uncertain	0.010	D
Polyphen		0.053	B
Vest4		0.25
MutPred		0.35		Loss of loop (P = 0.0112);
MVP		0.23
MPC		1.6
ClinPred		0.23	T
GERP RS		1.7
Varity_R		0.18
gMVP		0.43

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: rs2091436097; hg19: chrX-152954054;