rs746052951

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1_ModeratePM2PP5_Very_Strong

The NM_000022.4(ADA):​c.780+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000124 in 1,614,126 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

ADA
NM_000022.4 splice_donor, intron

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:2

Conservation

PhyloP100: 6.96

Publications

1 publications found
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]
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]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 12 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.093406595 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 20-44622828-C-T is Pathogenic according to our data. Variant chr20-44622828-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 242481.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ADANM_000022.4 linkc.780+1G>A splice_donor_variant, intron_variant Intron 8 of 11 ENST00000372874.9 NP_000013.2 P00813A0A0S2Z381
ADANM_001322051.2 linkc.708+1G>A splice_donor_variant, intron_variant Intron 7 of 10 NP_001308980.1 F5GWI4
ADANM_001322050.2 linkc.375+1G>A splice_donor_variant, intron_variant Intron 7 of 10 NP_001308979.1
ADANR_136160.2 linkn.872+1G>A splice_donor_variant, intron_variant Intron 8 of 10

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ADAENST00000372874.9 linkc.780+1G>A splice_donor_variant, intron_variant Intron 8 of 11 1 NM_000022.4 ENSP00000361965.4 P00813
ADAENST00000695995.1 linkc.390+1G>A splice_donor_variant, intron_variant Intron 5 of 8 ENSP00000512318.1 A0A8Q3SI64
ADAENST00000695991.1 linkc.318+1G>A splice_donor_variant, intron_variant Intron 4 of 7 ENSP00000512314.1 A0A0S2Z3B9
ADAENST00000696038.1 linkn.*602+1G>A splice_donor_variant, intron_variant Intron 7 of 8 ENSP00000512344.1 A0A8Q3SJ57

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152232
Hom.:
0
Cov.:
33
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
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251492
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461894
Hom.:
0
Cov.:
33
AF XY:
0.00000138
AC XY:
1
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112012
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152232
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74382
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10630
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:2
Revision: criteria provided, multiple submitters, no conflicts
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:1
Aug 27, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is present in population databases (rs746052951, ExAC 0.001%). This sequence change affects a donor splice site in intron 8 of the ADA gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in ADA are known to be pathogenic (PMID: 26255240, 26376800). Disruption of this splice site has been observed in individual(s) with atypical severe combined immunodeficiency (PMID: 21664875). ClinVar contains an entry for this variant (Variation ID: 242481). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Severe combined immunodeficiency disease Pathogenic:1
Nov 12, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: ADA c.780+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing and loss of ADA function. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 4e-06 in 251492 control chromosomes. c.780+1G>A has been reported in the literature in individuals affected with Severe Combined Immunodeficiency (Felgentreff_2011, Alizadeh_2023, la Marca_2013). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 37516813, 21664875, 23280131). ClinVar contains an entry for this variant (Variation ID: 242481). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
28
DANN
Uncertain
1.0
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.84
FATHMM_MKL
Pathogenic
0.98
D
PhyloP100
7.0
GERP RS
4.6
Mutation Taster
=1/99
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.93
SpliceAI score (max)
0.86
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.86
Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs746052951; hg19: chr20-43251469; API