chrX-77684520-G-A

Position:

• chrX-77684520-G-A

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_000489.6(ATRX):​c.736C>T​(p.Arg246Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000182 in 1,096,725 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 0.0000018 (0 hom. 0 hem.)
• Consequence: ATRX NM_000489.6 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:17 O:1
• Conservation: PhyloP100: 7.64

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 17 ACMG points.

• PM1: In a domain ADD (size 137) in uniprot entity ATRX_HUMAN there are 11 pathogenic changes around while only 0 benign (100%) in NM_000489.6
• PM2: Very rare variant in population databases, with high coverage
• 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, 0.983
• PP5: Variant X-77684520-G-A is Pathogenic according to our data. Variant chrX-77684520-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 11735.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-77684520-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ATRX	NM_000489.6	c.736C>T	p.Arg246Cys	missense_variant	9/35	ENST00000373344.11	NP_000480.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ATRX	ENST00000373344.11	c.736C>T	p.Arg246Cys	missense_variant	9/35	1	NM_000489.6	ENSP00000362441.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome AF: 0.00000182 AC: 2 AN: 1096725 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 362167

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: 0.00000238

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:17 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:7

Pathogenic, criteria provided, single submitter	clinical testing	Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen	Oct 23, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	May 19, 2022	Published functional studies demonstrate a damaging effect (Iwase et al., 2011; Dhayalan et al., 2011); Not observed in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 16955409, 27899421, 25590979, 9326931, 20500465, 24327140, 21666679, 21421568, 31130284, 32369273, 34051360, 17609377, 18409179) -
Likely pathogenic, criteria provided, single submitter	clinical testing	Laboratoire de Génétique Moléculaire, CHU Bordeaux	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 30, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Aug 01, 2018	- -
Pathogenic, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -

Alpha thalassemia-X-linked intellectual disability syndrome Pathogenic:6

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 26, 2023	This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 246 of the ATRX protein (p.Arg246Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with alpha-thalassemia X-linked intellectual disability syndrome (PMID: 9326931, 16955409, 20500465, 24327140). In at least one individual the variant was observed to be de novo. It has also been observed to segregate with disease in related individuals. This variant is also known as p.Arg129Cys. ClinVar contains an entry for this variant (Variation ID: 11735). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on ATRX protein function. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 15, 2020	Variant summary: ATRX c.736C>T (p.Arg246Cys) results in a non-conservative amino acid change located in the ADD (Zinc finger) 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 181349 control chromosomes. c.736C>T has been reported in the literature in multiple individuals affected with ATR-X Syndrome (example, Gibbons_1997, Wada_2000, Badens_2006, Pavone_2010, Monies_2019, Zhu_2015). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic (n=5)/likely pathogenic(n=1). Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Oct 15, 2006	- -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Human Genetics, Inc, Center for Human Genetics, Inc	Nov 01, 2016	- -
Pathogenic, criteria provided, single submitter	research	Division of Human Genetics, National Health Laboratory Service/University of the Witwatersrand	Jul 01, 2023	- -

Intellectual disability-hypotonic facies syndrome, X-linked, 1 Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	3billion	Jan 03, 2022	The variant has been observed in multiple (>3) similarly affected unrelated individuals (PMID: 16955409, 20500465, 31130284, PS4_S). The variant was co-segregated with Mental retardation-hypotonic facies syndrome, X-linked in multiple affected family members (PMID: 20500465, PP1_P). In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.972, 3CNET: 0.905, PP3_P). A missense variant is a common mechanism associated with Mental retardation-hypotonic facies syndrome (PP2_P). It is not observed in the gnomAD v2.1.1 dataset (PM2_M). A different missense change at the same codon has been reported to be associated with ATRX related disorder (PMID:10660327, PM5_P). Therefore, this variant is classified as pathogenic according to the recommendation of ACMG/AMP guideline. -
Likely pathogenic, no assertion criteria provided	clinical testing	Centre de Biologie Pathologie Génétique, Centre Hospitalier Universitaire de Lille	Jan 01, 2019	- -

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 03, 2013

​ -

Acquired hemoglobin H disease;C1845055:Alpha thalassemia-X-linked intellectual disability syndrome;C4759781:Intellectual disability-hypotonic facies syndrome, X-linked, 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Renier-Gabreels-Jasper syndrome Other:1

not provided, no classification provided

phenotyping only

GenomeConnect, ClinGen

-

Variant interpretted as Pathogenic and reported on 01-31-2016 by Lab or GTR ID 506634. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.71	D
BayesDel_noAF	Pathogenic	0.78
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.44	.;.;T;T;.
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;.;D;D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-4.5	D;D;.;.;.
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D;.;.;.
Sift4G	Pathogenic	0.0	D;D;D;.;D
Polyphen		1.0	D;.;.;.;.
Vest4		0.91
MutPred		0.90		Gain of ubiquitination at K251 (P = 0.0341);.;.;Gain of ubiquitination at K251 (P = 0.0341);.;
MVP		1.0
MPC		2.6
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
gMVP		0.94

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: rs122445105; hg19: chrX-76940012; COSMIC: COSV64872639; COSMIC: COSV64872639;