rs1557097008

Variant names:

• chrX-77616643-G-A
• rs1557097008
• NM_000489.6:c.5536C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000489.6(ATRX):​c.5536C>T​(p.Leu1846Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. L1846L) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 23)
• Consequence: ATRX NM_000489.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.70
• Publications: 0 publications found

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]

ATRX Gene-Disease associations (from GenCC):

• alpha thalassemia-X-linked intellectual disability syndrome

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics
• ATR-X-related syndrome

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• intellectual disability-hypotonic facies syndrome, X-linked, 1

  Inheritance: XL Classification: MODERATE Submitted by: Ambry Genetics

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 4 uncertain in NM_000489.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.963

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ATRX	NM_000489.6	c.5536C>T	p.Leu1846Phe	missense_variant	Exon 22 of 35	ENST00000373344.11	NP_000480.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ATRX	ENST00000373344.11	c.5536C>T	p.Leu1846Phe	missense_variant	Exon 22 of 35	1	NM_000489.6	ENSP00000362441.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Alpha thalassemia-X-linked intellectual disability syndrome Uncertain:1

Oct 23, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals with a ATRX-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces leucine with phenylalanine at codon 1846 of the ATRX protein (p.Leu1846Phe). The leucine residue is highly conserved and there is a small physicochemical difference between leucine and phenylalanine. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, this variant has uncertain impact on ATRX function. The available evidence is currently insufficient to determine its role 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	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Uncertain	25
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.65	.;.;D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;.;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.96	D;D;D
MetaSVM	Pathogenic	1.0	D
PhyloP100		7.7
PrimateAI	Pathogenic	0.85	D
PROVEAN	Uncertain	-3.5	D;D;.
REVEL	Pathogenic	0.87
Sift	Uncertain	0.0010	D;D;.
Sift4G	Uncertain	0.0030	D;D;T
Vest4		0.63
MutPred		0.81		Loss of catalytic residue at L1846 (P = 0.1225);.;.;
MVP		0.98
MPC		2.7
ClinPred		1.0	D
GERP RS		5.8
gMVP		0.91
Mutation Taster		=35/65	disease causing

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

Other links and lift over

dbSNP: rs1557097008; hg19: chrX-76872111; COSMIC: COSV64874294;