chrX-153688833-G-A

Variant names:

• chrX-153688833-G-A
• rs122453115
• NM_005629.4:c.259G>A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PS3_Supporting PP3 PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The NM_005629.4:c.259G>A variant in SLC6A8 is a missense variant predicted to cause substitution of glycine by arginine at amino acid 87 (p.Gly87Arg). This variant is absent in population databases (PM2_Supporting) and has been described in the literature in an individual for whom biochemical testing could not be performed (PMID:15154114). The computational predictor REVEL gives a score of 0.961 which is above the thresholds predicting a damaging (>0.75) impact on SLC6A8 function (PP3). When fibroblasts deficient for this SLC6A8 variant were grown in the presence of a physiological Cr concentration (25uM), the average creatine uptake was just above the detection limit, whereas in the control fibroblasts it was significantly higher (PMID:17465020) (PS3_Supporting). There is a ClinVar entry for this variant (Variation ID:11700). In summary, this variant meets the criteria to be classified as a Variant of Uncertain Significance for Creatine Transporter Deficiency. SLC6A8-specific ACMG/AMP criteria applied, as specified by the ClinGen Cerebral Creatine Deficiency Syndromes Variant Curation Expert Panel (Specifications Version 1.1.0): PP3, PS3_Supporting, PM2_Supporting.(Classification approved by the ClinGen CCDS VCEP, July 13, 2023) LINK:https://erepo.genome.network/evrepo/ui/classification/CA256012/MONDO:0010305/027

• Frequency:
  • Genomes: not found (cov: 21)
  • Exomes 𝑓: 0.0 (0 hom. 0 hem.)
  • Failed GnomAD Quality Control
• Consequence: SLC6A8 NM_005629.4 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:2 U:1
• Conservation: PhyloP100: 9.18

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 3 ACMG points.

• PS3: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC6A8	NM_005629.4	c.259G>A	p.Gly87Arg	missense_variant	Exon 1 of 13	ENST00000253122.10	NP_005620.1
SLC6A8	NM_001142805.2	c.259G>A	p.Gly87Arg	missense_variant	Exon 1 of 13		NP_001136277.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC6A8	ENST00000253122.10	c.259G>A	p.Gly87Arg	missense_variant	Exon 1 of 13	1	NM_005629.4	ENSP00000253122.5

Frequencies

GnomAD3 genomes Cov.: 21

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 998799 Hom.: 0 Cov.: 26 AF XY: 0.00 AC XY: 0 AN XY: 315857

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 21

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:2 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Creatine transporter deficiency Pathogenic:1 Uncertain:1

Aug 24, 2023

ClinGen Cerebral Creatine Deficiency Syndromes Variant Curation Expert Panel, ClinGen

Significance: Uncertain significance

Review Status: reviewed by expert panel

Collection Method: curation

The NM_005629.4:c.259G>A variant in SLC6A8 is a missense variant predicted to cause substitution of glycine by arginine at amino acid 87 (p.Gly87Arg). This variant is absent in population databases (PM2_Supporting) and has been described in the literature in an individual for whom biochemical testing could not be performed (PMID: 15154114). The computational predictor REVEL gives a score of 0.961 which is above the thresholds predicting a damaging (>0.75) impact on SLC6A8 function (PP3). When fibroblasts deficient for this SLC6A8 variant were grown in the presence of a physiological Cr concentration (25uM), the average creatine uptake was just above the detection limit, whereas in the control fibroblasts it was significantly higher (PMID: 17465020) (PS3_Supporting). There is a ClinVar entry for this variant (Variation ID:11700). In summary, this variant meets the criteria to be classified as a Variant of Uncertain Significance for Creatine Transporter Deficiency. SLC6A8-specific ACMG/AMP criteria applied, as specified by the ClinGen Cerebral Creatine Deficiency Syndromes Variant Curation Expert Panel (Specifications Version 1.1.0): PP3, PS3_Supporting, PM2_Supporting. (Classification approved by the ClinGen CCDS VCEP, July 13, 2023) -

Jul 01, 2004

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided Pathogenic:1

Jun 24, 2020

Mayo Clinic Laboratories, Mayo Clinic

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PS3, PM2, PP3, PM6 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.73	D
BayesDel_noAF	Pathogenic	0.81
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.78	D
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	1.0	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.4	H
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-7.0	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.92
MutPred		0.95		Gain of methylation at G87 (P = 0.0254);
MVP		1.0
MPC		2.6
ClinPred		1.0	D
GERP RS		2.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.94
gMVP		1.0

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: rs122453115; hg19: chrX-152954288;