rs122445111

Positions:

• chrX-77684942-C-T

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000489.6(ATRX):​c.659G>A​(p.Cys220Tyr) 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C220R) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 24)
• Consequence: ATRX NM_000489.6 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.54

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 Pathogenic. Variant got 19 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 2 uncertain in NM_000489.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), ATRX. . Gene score misZ 3.1025 (greater than the threshold 3.09). GenCC has associacion of gene with alpha thalassemia-X-linked intellectual disability syndrome, ATR-X-related syndrome, intellectual disability-hypotonic facies syndrome, X-linked, 1.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant X-77684942-C-T is Pathogenic according to our data. Variant chrX-77684942-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 11745.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ATRX	NM_000489.6	c.659G>A	p.Cys220Tyr	missense_variant	8/35	ENST00000373344.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ATRX	ENST00000373344.11	c.659G>A	p.Cys220Tyr	missense_variant	8/35	1	NM_000489.6	P3

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 24

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 06, 2016

- -

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

Likely pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Aug 10, 2021

Variant summary: ATRX c.659G>A (p.Cys220Tyr) results in a non-conservative amino acid change located in the ADD domain (IPR025766) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 183067 control chromosomes (gnomAD). c.659G>A has been reported in the literature co-segregating with disease in a family with multiple individuals affected with ATR-X Syndrome (Stevenson_2000). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. A ClinVar submitter (evaluation after 2014) cites the variant as pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Intellectual disability-hypotonic facies syndrome, X-linked Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Oct 23, 2000

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.70	D
BayesDel_noAF	Pathogenic	0.77
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.47	.;.;T;T;.
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.97	D;.;D;D;D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	A;A
PrimateAI	Pathogenic	0.96	D
PROVEAN	Pathogenic	-5.8	D;D;.;.;.
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;D;.;.;.
Sift4G	Pathogenic	0.0010	D;D;D;.;D
Polyphen		1.0	D;.;.;.;.
Vest4		0.93
MutPred		0.94		Gain of loop (P = 0.0851);.;.;Gain of loop (P = 0.0851);.;
MVP		1.0
MPC		3.0
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
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: rs122445111; hg19: chrX-76940434;