X-77522375-C-T

Variant names:

• chrX-77522375-C-T
• rs1135401774
• NM_000489.6:c.6863G>A

Variant summary

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

The NM_000489.6(ATRX):​c.6863G>A​(p.Arg2288His) variant causes a missense change. The variant allele was found at a frequency of 0.000000912 in 1,097,042 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 22)
  • Exomes 𝑓: 9.1e-7 (0 hom. 0 hem.)
• Consequence: ATRX NM_000489.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.95

Genes affected

ATRX (HGNC:886): (ATRX chromatin remodeler) The protein encoded by this gene contains an ATPase/helicase domain, and thus it belongs to the SWI/SNF family of chromatin remodeling proteins. This protein is found to undergo cell cycle-dependent phosphorylation, which regulates its nuclear matrix and chromatin association, and suggests its involvement in the gene regulation at interphase and chromosomal segregation in mitosis. Mutations in this gene are associated with X-linked syndromes exhibiting cognitive disabilities as well as alpha-thalassemia (ATRX) syndrome. These mutations have been shown to cause diverse changes in the pattern of DNA methylation, which may provide a link between chromatin remodeling, DNA methylation, and gene expression in developmental processes. Multiple alternatively spliced transcript variants encoding distinct isoforms have been reported. [provided by RefSeq, Jul 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ATRX	NM_000489.6	c.6863G>A	p.Arg2288His	missense_variant	Exon 32 of 35	ENST00000373344.11	NP_000480.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ATRX	ENST00000373344.11	c.6863G>A	p.Arg2288His	missense_variant	Exon 32 of 35	1	NM_000489.6	ENSP00000362441.4

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome AF: 9.12e-7 AC: 1 AN: 1097042 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 362746

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: 0.00000119

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 22

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Alpha thalassemia-X-linked intellectual disability syndrome Uncertain:2

Jun 09, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 2288 of the ATRX protein (p.Arg2288His). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of ATRX-related conditions (PMID: 29158550). ClinVar contains an entry for this variant (Variation ID: 431097). 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: "Benign"; Align-GVGD: "Class C0"). 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. -

Aug 01, 2017

Institute of Human Genetics, FAU Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Missense variant in ATRX identified in a male, 16 mo with hypotonia, severe developmental delay, renal anomalies, normal head circumference. The variant was inherited from the healthy mother who had a XI of 86%. The missense variant c.6863G>A, p.(Arg2288His) in ATRX is located downstream of the two functional domains harboring approximately 80% of mutations but affects a highly conserved amino acid. Pathogenic relevance might be confirmed by determining Hb inclusion bodies in erythrocytes. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.45
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	0.0
CADD	Uncertain	25
DANN	Uncertain	0.98
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D;.
M_CAP	Pathogenic	0.68	D
MetaRNN	Uncertain	0.47	T;T
MetaSVM	Uncertain	0.71	D
PrimateAI	Uncertain	0.76	T
PROVEAN	Uncertain	-2.4	N;N
REVEL	Uncertain	0.61
Sift	Benign	0.095	T;T
Sift4G	Benign	0.13	T;T
Vest4		0.21
MVP		0.94
MPC		1.9
ClinPred		0.92	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
gMVP		0.62

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1135401774; hg19: chrX-76777853;