rs114025668
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PP3_Moderate
The NM_000022.4(ADA):c.643G>A(p.Ala215Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000613 in 1,614,108 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A215A) has been classified as Likely benign.
Frequency
Consequence
NM_000022.4 missense
Scores
Clinical Significance
Conservation
Publications
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ACMG classification
Our verdict: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt | 
|---|---|---|---|---|---|---|---|---|
| ADA | NM_000022.4 | c.643G>A | p.Ala215Thr | missense_variant | Exon 7 of 12 | ENST00000372874.9 | NP_000013.2 | |
| ADA | NM_001322050.2 | c.238G>A | p.Ala80Thr | missense_variant | Exon 6 of 11 | NP_001308979.1 | ||
| ADA | NR_136160.2 | n.735G>A | non_coding_transcript_exon_variant | Exon 7 of 11 | ||||
| ADA | NM_001322051.2 | c.607-112G>A | intron_variant | Intron 6 of 10 | NP_001308980.1 | 
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt | 
|---|---|---|---|---|---|---|---|---|---|---|
| ADA | ENST00000372874.9 | c.643G>A | p.Ala215Thr | missense_variant | Exon 7 of 12 | 1 | NM_000022.4 | ENSP00000361965.4 | ||
| ADA | ENST00000695995.1 | c.253G>A | p.Ala85Thr | missense_variant | Exon 4 of 9 | ENSP00000512318.1 | ||||
| ADA | ENST00000696038.1 | n.*389G>A | non_coding_transcript_exon_variant | Exon 7 of 9 | ENSP00000512344.1 | |||||
| ADA | ENST00000696038.1 | n.*389G>A | 3_prime_UTR_variant | Exon 7 of 9 | ENSP00000512344.1 | |||||
| ADA | ENST00000695991.1 | c.217-112G>A | intron_variant | Intron 3 of 7 | ENSP00000512314.1 | 
Frequencies
GnomAD3 genomes  0.000276  AC: 42AN: 152160Hom.:  0  Cov.: 33 show subpopulations 
GnomAD2 exomes  AF:  0.0000994  AC: 25AN: 251422 AF XY:  0.0000736   show subpopulations 
GnomAD4 exome  AF:  0.0000390  AC: 57AN: 1461828Hom.:  0  Cov.: 33 AF XY:  0.0000358  AC XY: 26AN XY: 727210 show subpopulations 
Age Distribution
GnomAD4 genome  0.000276  AC: 42AN: 152280Hom.:  0  Cov.: 33 AF XY:  0.000269  AC XY: 20AN XY: 74454 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
Severe combined immunodeficiency, autosomal recessive, T cell-negative, B cell-negative, NK cell-negative, due to adenosine deaminase deficiency    Uncertain:6Other:1 
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
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This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 215 of the ADA protein (p.Ala215Thr). This variant is present in population databases (rs114025668, gnomAD 0.07%). This missense change has been observed in individual(s) with partial ADA deficiency without SCID (PMID: 2166947, 9108404, 9225964, 9758612, 14499267). ClinVar contains an entry for this variant (Variation ID: 1967). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) 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: 2166947, 9108404, 9361033, 11067872). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Partial adenosine deaminase deficiency    Pathogenic:1 
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not specified    Uncertain:1 
Variant summary: ADA c.643G>A (p.Ala215Thr) results in a non-conservative amino acid change located in the Adenosine/AMP deaminase domain (IPR001365) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. Consensus agreement among computation tools predict no significant impact on normal splicing. However, at least one publication reports experimental evidence that this variant affects mRNA splicing resulting in induction of exon 7 skipping in approximately 50% of cells (Ozsahin_1997) but a residual low level (10-15%) skipping of exon 7 was also observed in normal cells. Therefore, the exact impact of this splicing phenomenon on ADA activity in-vivo is not clear.. The variant allele was found at a frequency of 9.9e-05 in 251422 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in ADA causing Severe Combined Immunodeficiency (9.9e-05 vs 0.0014), allowing no conclusion about variant significance. c.643G>A has been not been reported in the literature in individuals affected with Severe Combined Immunodeficiency Syndrome, but has been observed in clinically asymptomatic individuals presenting with a partial ADA deficiency in-vitro (example, Hirschhorn_1990, Hirschhorn_1997, Ozsahin_1997).. These report(s) do not provide unequivocal conclusions about association of the variant with Severe Combined Immunodeficiency. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal ADA enzyme activity (example, Jiang_1997, Richard_2007, Arredondo-Vega_1998). The following publications have been ascertained in the context of this evaluation (PMID: 9225964, 14499267, 9758612, 9108404, 21664875, 2166947, 9361033, 11067872). ClinVar contains an entry for this variant (Variation ID: 1967). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at