X-135985520-G-C

Position:

• chrX-135985520-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The ENST00000370695.8(SLC9A6):​c.18G>C​(p.Trp6Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict 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. W6R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 22)
  • Exomes 𝑓: 0.0 (0 hom. 0 hem.)
  • Failed GnomAD Quality Control
• Consequence: SLC9A6 ENST00000370695.8 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.968

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.28691417).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SLC9A6	NM_001379110.1	c.-57+43G>C		intron_variant		ENST00000630721.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SLC9A6	ENST00000630721.3	c.-57+43G>C		intron_variant		4	NM_001379110.1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1009665 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 317513

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.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jan 12, 2021

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Christianson syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 28, 2023

This missense change has been observed to be homozygous or hemizygous in an individual who did not have the expected clinical features for that genetic result (Invitae). This sequence change replaces tryptophan, which is neutral and slightly polar, with cysteine, which is neutral and slightly polar, at codon 6 of the SLC9A6 protein (p.Trp6Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SLC9A6-related conditions. ClinVar contains an entry for this variant (Variation ID: 450956). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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	Uncertain	0.35
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.44
CADD	Benign	19
DANN	Benign	0.97
DEOGEN2	Benign	0.12	.;T
FATHMM_MKL	Benign	0.59	D
LIST_S2	Benign	0.83	T;T
M_CAP	Pathogenic	0.96	D
MetaRNN	Benign	0.29	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.69	N;N
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.89	D
PROVEAN	Benign	-0.55	N;N
REVEL	Benign	0.11
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.016	D;D
Polyphen		0.42	B;B
Vest4		0.35
MutPred		0.31		Gain of methylation at R4 (P = 0.0227);Gain of methylation at R4 (P = 0.0227);
MVP		0.17
MPC		1.6
ClinPred		0.61	D
GERP RS		4.9
Varity_R		0.32
gMVP		0.68

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: rs1012532789; hg19: chrX-135067679;