Is ADA2 p.Asn100= (c.300T>C) pathogenic?

ADA2 p.Asn100= (c.300T>C) is classified Likely benign in ADA2 (ClinVar, Single submitter, 1 submitter; last evaluated 2024-11-11). Very rare (popmax 0.000593%, nfe); Associated with deficiency of adenosine deaminase 2.

What condition is associated with ADA2 p.Asn100= (c.300T>C)?

ADA2 p.Asn100= (c.300T>C) is associated with deficiency of adenosine deaminase 2 (ClinVar).

How common is ADA2 p.Asn100= (c.300T>C) in the general population?

ADA2 p.Asn100= (c.300T>C) is very rare (popmax 0.000593%, nfe) (gnomAD).

How is Deficiency of adenosine deaminase 2 inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

ADA2 p.Asn100=

c.300T>C · rs776766882 · VCV1094203

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.000593%, nfe)

Conditions

deficiency of adenosine deaminase 2

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -1.7	GERP -3.1
Overall
CADD	0.219	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000593% European (non-Finnish) · 7/1,179,988 alleles

Filtering AF 0.000247% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000159%

Overall 0.000547% 8/1,461,830 alleles · very rare

Ancestry group	Frequency	1 in
Remaining individualsnot grpmax-eligible	0.0016%	62,512
European (non-Finnish)grpmax	0.000593%	168,570

Remaining individuals shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: ADA2
Protein: p.Asn100=
Coding: c.300T>C
MANE Select: NM_001166105 · reported on NM_001282225
dbSNP: rs776766882
Type: single nucleotide variant
Location: chr22:17209378 (GRCh38)
Structure: AlphaFold pLDDT 85.04 · 1 PDB
Residue 100: the sant domain; an α-helix

Full ADA2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

deficiency of adenosine deaminase 2 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Deficiency of adenosine deaminase 2 (Orphanet):

Inheritance: Autosomal recessive
Onset: Childhood, Infancy
Prevalence: <1 / 1 000 000 (Worldwide)

Similar variants

ADA2 p.Asn100Tyr Uncertain significance ★ ⚠ same residue
ADA2 c.754-2A>G Likely pathogenic ★★ same condition
ADA2 c.882-2A>G Pathogenic ★★ same condition
ADA2 c.973-2A>G Pathogenic ★★ same condition
ADA2 p.Arg169Gln Pathogenic/Likely pathogenic ★★ ⚠ same condition
ADA2 p.Arg169Trp Pathogenic/Likely pathogenic ★★ same condition
ADA2 p.Arg306Ter Likely pathogenic ★★ same condition
ADA2 p.Arg312Ter Pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/ada2-p-asn100 (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown