X-135985509-C-T

Position:

• chrX-135985509-C-T

Variant summary

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

The ENST00000370695.8(SLC9A6):​c.7C>T​(p.Arg3Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000303 in 991,574 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 1 hemizygotes 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. R3L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 22)
  • Exomes 𝑓: 0.0000030 (0 hom. 1 hem.)
• Consequence: SLC9A6 ENST00000370695.8 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.455

Genes affected

SLC9A6 (HGNC:11079): (solute carrier family 9 member A6) This gene encodes a sodium-hydrogen exchanger that is amember of the solute carrier family 9. The encoded protein localizes to early and recycling endosomes and may be involved in regulating endosomal pH and volume. Defects in this gene are associated with X-linked syndromic cognitive disability, Christianson type. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Apr 2010]

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=0.22889367).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SLC9A6	NM_001379110.1	c.-57+32C>T		intron_variant		ENST00000630721.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SLC9A6	ENST00000630721.3	c.-57+32C>T		intron_variant		4	NM_001379110.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome AF: 0.00000303 AC: 3 AN: 991574 Hom.: 0 Cov.: 29 AF XY: 0.00000321 AC XY: 1 AN XY: 311118

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: 0.00000378

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

SLC9A6-related disorder Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Jan 11, 2023

The SLC9A6 c.7C>T variant is predicted to result in the amino acid substitution p.Arg3Trp. To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Christianson syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 14, 2022

This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 3 of the SLC9A6 protein (p.Arg3Trp). This missense change has been observed in individual(s) with epilepsy (Invitae). It has also been observed to segregate with disease in related individuals. 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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 657261). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.34
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.51
CADD	Benign	17
DANN	Uncertain	1.0
FATHMM_MKL	Benign	0.18	N
LIST_S2	Benign	0.80	T;T
M_CAP	Pathogenic	0.83	D
MetaRNN	Benign	0.23	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.2	L;L
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Pathogenic	0.92	D
PROVEAN	Benign	-0.16	N;N
REVEL	Benign	0.086
Sift	Uncertain	0.011	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		0.91	P;P
Vest4		0.23
MutPred		0.40		Loss of disorder (P = 0.0575);Loss of disorder (P = 0.0575);
MVP		0.18
MPC		1.1
ClinPred		0.68	D
GERP RS		3.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.14
gMVP		0.62

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1556614701; hg19: chrX-135067668;