rs121908740

Positions:

chr20-44623054-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PP1_ModeratePM5PM3

This summary comes from the ClinGen Evidence Repository: NM_000022.4:c.631C>T is a missense variant predicted to cause substitution of Arginine by Cysteine at amino acid 211 (p. Arg211Cys). The highest population minor allele frequency in gnomAD v4 is 0.0005167 (31/60000) in Admixed American population (PM2_Supporting, BS1, and BA1 are not met). The variant has been reported to segregate with SCID in 2 affected family members from 1 family (PP1_moderate; PMID :8051429). Patient was found heterozygous for R211C & L107P which is classified as likely pathogenic by SCID VCEP (1 pt.) (PM3) (PMID:2166947).Another missense variant [c.632G>A, p.Arg211His)] in the same codon has been classified as pathogenic for SCID by the ClinGen SCID VCEP (PM5).In summary, this variant meets the criteria to be classified as a Likely Pathogenic variant for autosomal recessive severe combined immunodeficiency due to ADA deficiency based on the ACMG/AMP criteria applied, as specified by the ClinGen SCID VCEP: PP1_moderate,PM3,PM5(VCEP specifications version 1). LINK:https://erepo.genome.network/evrepo/ui/classification/CA115285/MONDO:0007064/114

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000035 ( 0 hom. )

Consequence

ADA
ENST00000372874.9 missense

Scores

Clinical Significance

Likely pathogenic reviewed by expert panel P:9U:1O:1

Conservation

PhyloP100: 5.17

Variant links:

Genes affected

ADA (HGNC:186): (adenosine deaminase) This gene encodes an enzyme that catalyzes the hydrolysis of adenosine to inosine in the purine catabolic pathway. Various mutations have been described for this gene and have been linked to human diseases related to impaired immune function such as severe combined immunodeficiency disease (SCID) which is the result of a deficiency in the ADA enzyme. In ADA-deficient individuals there is a marked depletion of T, B, and NK lymphocytes, and consequently, a lack of both humoral and cellular immunity. Conversely, elevated levels of this enzyme are associated with congenital hemolytic anemia. [provided by RefSeq, Sep 2019]

ADA links:

PKIG (HGNC:9019): (cAMP-dependent protein kinase inhibitor gamma) This gene encodes a member of the protein kinase inhibitor family. Studies of a similar protein in mice suggest that this protein acts as a potent competitive cAMP-dependent protein kinase inhibitor, and is a predominant form of inhibitor in various tissues. The encoded protein may be involved in osteogenesis. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

PKIG links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM3

For more information check the summary or visit ClinGen Evidence Repository.

PM5

For more information check the summary or visit ClinGen Evidence Repository.

PP1

For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein
ADA	NM_000022.4 linkuse as main transcript	c.631C>T	p.Arg211Cys	missense_variant	7/12	ENST00000372874.9	NP_000013.2
ADA	NM_001322050.2 linkuse as main transcript	c.226C>T	p.Arg76Cys	missense_variant	6/11		NP_001308979.1
ADA	NM_001322051.2 linkuse as main transcript	c.607-124C>T		intron_variant			NP_001308980.1
ADA	NR_136160.2 linkuse as main transcript	n.723C>T		non_coding_transcript_exon_variant	7/11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ADA	ENST00000372874.9 linkuse as main transcript	c.631C>T	p.Arg211Cys	missense_variant	7/12	1	NM_000022.4	ENSP00000361965	P4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152200

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000127

AC:

AN:

251340

Hom.:

AF XY:

0.000110

AC XY:

AN XY:

135844

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000694

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.000815

GnomAD4 exome

AF:

0.0000349

AC:

AN:

1461770

Hom.:

Cov.:

AF XY:

0.0000330

AC XY:

AN XY:

727182

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000693

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000126

Gnomad4 OTH exome

AF:

0.0000828

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152200

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74354

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000425

Hom.:

Bravo

AF:

0.0000340

ExAC

AF:

0.000107

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:9Uncertain:1Other:1

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Severe combined immunodeficiency, autosomal recessive, T cell-negative, B cell-negative, NK cell-negative, due to adenosine deaminase deficiency

Pathogenic:7Uncertain:1Other:1

Likely pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Uncertain significance, flagged submission	clinical testing	Counsyl	May 10, 2018	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Nov 01, 2018	The ADA c.631C>T (p.Arg211Cys) variant was first reported by Hirschhorn et al. (1990) in a child with partial adenosine deaminase (ADA) deficiency. This patient was compound heterozygous for p.Arg211Cys and a second missense variant, and had approximately 8% residual ADA activity in lymphoid cells. The p.Arg211Cys variant was subsequently identified in a compound heterozygous state with a second deletion variant in two siblings with ADA deficiency and combined immunodeficiency, with no detectable ADA activity. The p.Arg211Cys variant was also detected in a heterozygous state in the mother, two additional siblings, and in a patient's child, all of whom had normal or below normal ADA activity (Shovlin et al. 1994). Control data are unavailable for this variant, but it is reported at a frequency of 0.00078 in the Latino population of the Exome Aggregation Consortium. Expression studies in COS cells by Jiang et al. (1997) showed that the p.Arg211Cys variant resulted in residual ADA activity of approximately 4% of normal. Another variant at this position, p.Arg211His, has also been seen in patients with ADA deficiency (Akeson et al. 1988; Arredondo-Vega et al. 1998). Based on the collective evidence, the p.Arg211Cys variant is classified as likely pathogenic for adenosine deaminase deficiency. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 17, 2024	This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 211 of the ADA protein (p.Arg211Cys). This variant is present in population databases (rs121908740, gnomAD 0.07%). This missense change has been observed in individual(s) with adenosine deaminase deficiency (PMID: 2166947, 8051429, 9616253). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 1966). 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) performed at Invitae indicates that this missense variant is not expected to disrupt ADA protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change affects ADA function (PMID: 9361033, 9758612). This variant disrupts the p.Arg211 amino acid residue in ADA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 1974554, 9414266, 9758612, 26376800). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Aug 10, 2021	- -
not provided, no classification provided	literature only	UniProtKB/Swiss-Prot	-	- -
Pathogenic, criteria provided, single submitter	curation	Laboratory of Medical Genetics, National & Kapodistrian University of Athens	Feb 01, 2024	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 25, 2024	- -
Likely pathogenic, reviewed by expert panel	curation	ClinGen Severe Combined Immunodeficiency Variant Curation Expert Panel, ClinGen	Jan 10, 2024	NM_000022.4:c.631C>T is a missense variant predicted to cause substitution of Arginine by Cysteine at amino acid 211 (p. Arg211Cys). The highest population minor allele frequency in gnomAD v4 is 0.0005167 (31/60000) in Admixed American population (PM2_Supporting, BS1, and BA1 are not met). The variant has been reported to segregate with SCID in 2 affected family members from 1 family (PP1_moderate; PMID :8051429). Patient was found heterozygous for R211C & L107P which is classified as likely pathogenic by SCID VCEP (1 pt.) (PM3) (PMID: 2166947).Another missense variant [c.632G>A, p.Arg211His)] in the same codon has been classified as pathogenic for SCID by the ClinGen SCID VCEP (PM5). In summary, this variant meets the criteria to be classified as a Likely Pathogenic variant for autosomal recessive severe combined immunodeficiency due to ADA deficiency based on the ACMG/AMP criteria applied, as specified by the ClinGen SCID VCEP: PP1_moderate,PM3,PM5(VCEP specifications version 1). -

Partial adenosine deaminase deficiency

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Sep 01, 1994

- -

Severe combined immunodeficiency disease

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

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

Sep 26, 2022

Variant summary: ADA c.631C>T (p.Arg211Cys) results in a non-conservative amino acid change located in the adenosine deaminase domain (IPR001365) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00013 in 251340 control chromosomes, predominantly at a frequency of 0.00069 within the Latino subpopulation in the gnomAD database. This frequency is not higher than expected for a pathogenic variant in ADA causing Severe Combined Immunodeficiency (0.00013 vs 0.0014), allowing no conclusion about variant significance. c.631C>T has been reported in the literature as a compound heterozygous genotype in an individual with partial ADA deficiency, detected as 8% ADA activity in lymphoid cells, and in two siblings affected with late onset severe combined immunodeficiency with ADA deficiency, where the variant segregated with disease in the family (e.g. Hirschhorn_1990, Shovlin_1994). Multiple publications report evidence evaluating an impact on protein function (e.g. Hirschhorn_1990, Jiang_1997, Arredondo-Vega_1998) and experiments expressing the variant in an in vitro model system found that the variant results in <5% of normal activity. Another variant, p.Arg211His, affecting the same amino acid residue has also been observed in individuals with severe combined immunodeficiency and has been classified as pathogenic (ClinVar ID: 1957). Five submitters have provided clinical-significance assessments for this variant to ClinVar after 2014. The majority classified the variant as either pathogenic (n=1) or likely pathogenic (n=3), and one classified it as VUS. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Pathogenic

0.46

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.94

Eigen

Uncertain

0.29

Eigen_PC

Uncertain

0.23

FATHMM_MKL

Uncertain

0.88

LIST_S2

Uncertain

0.92

M_CAP

Pathogenic

0.54

MetaRNN

Pathogenic

0.98

MetaSVM

Pathogenic

0.99

MutationAssessor

Uncertain

2.3

MutationTaster

Benign

1.0

A;A;A;A

PrimateAI

Uncertain

0.56

PROVEAN

Pathogenic

-7.2

REVEL

Pathogenic

0.88

Sift

Uncertain

0.014

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.95

MutPred

0.87

Loss of methylation at R211 (P = 0.0329);

MVP

0.95

MPC

0.61

ClinPred

0.79

GERP RS

4.0

Varity_R

0.80

gMVP

0.91

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over