chr20-44625628-C-G

Position:

• chr20-44625628-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Strong

The NM_000022.4(ADA):​c.419G>C​(p.Gly140Ala) 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G140E) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ADA NM_000022.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.54

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr20-44625628-C-T is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.968

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ADA	NM_000022.4	c.419G>C	p.Gly140Ala	missense_variant	5/12	ENST00000372874.9	NP_000013.2
ADA	NM_001322051.2	c.419G>C	p.Gly140Ala	missense_variant	5/11		NP_001308980.1
ADA	NM_001322050.2	c.73+828G>C		intron_variant			NP_001308979.1
ADA	NR_136160.2	n.511G>C		non_coding_transcript_exon_variant	5/11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ADA	ENST00000372874.9	c.419G>C	p.Gly140Ala	missense_variant	5/12	1	NM_000022.4	ENSP00000361965	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.40
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D;D
Eigen	Pathogenic	0.70
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Uncertain	0.75	D
MutationAssessor	Uncertain	2.2	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.50	T
PROVEAN	Pathogenic	-5.0	D;D
REVEL	Pathogenic	0.82
Sift	Benign	0.086	T;D
Sift4G	Benign	0.31	T;T
Polyphen		1.0	D;.
Vest4		0.72
MutPred		0.89		Loss of disorder (P = 0.1092);Loss of disorder (P = 0.1092);
MVP		0.94
MPC		0.64
ClinPred		0.99	D
GERP RS		5.6
Varity_R		0.79
gMVP		0.86

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: rs121908732; hg19: chr20-43254269;