12-8605227-T-G

Variant names:

• chr12-8605227-T-G
• rs104894322
• NM_020661.4:c.415A>C

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM2 PM5 PP2 PP3_Strong

The NM_020661.4(AICDA):​c.415A>C​(p.Met139Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,726 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. M139T) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: AICDA NM_020661.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.45
• Publications: 0 publications found

Genes affected

AICDA (HGNC:13203): (activation induced cytidine deaminase) This gene encodes a RNA-editing deaminase that is a member of the cytidine deaminase family. AICDA is specifically expressed and active in germinal center-like B cells. In the germinal center, AICDA is involved in somatic hypermutation, gene conversion, and class-switch recombination of immunoglobulin genes. An epigenetic role in neoplastic transformation and lymphoma progression has been experimentally ascribed to AICDA using mouse models. Defects in this gene are the cause of autosomal recessive hyper-IgM immunodeficiency syndrome type 2 (HIGM2). [provided by RefSeq, Jul 2020]

AICDA Gene-Disease associations (from GenCC):

• hyper-IgM syndrome type 2

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-8605226-A-G is described in ClinVar as Pathogenic. ClinVar VariationId is 636339.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 13 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 1.3381 (below the threshold of 3.09). Trascript score misZ: 0.98605 (below the threshold of 3.09). GenCC associations: The gene is linked to hyper-IgM syndrome type 2.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.978

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020661.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AICDA	NM_020661.4	MANE Select	c.415A>C	p.Met139Leu	missense	Exon 3 of 5	NP_065712.1
	AICDA	NM_001330343.2		c.415A>C	p.Met139Leu	missense	Exon 3 of 5	NP_001317272.1
	AICDA	NM_001410970.1		c.415A>C	p.Met139Leu	missense	Exon 3 of 4	NP_001397899.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AICDA	ENST00000229335.11	TSL:1 MANE Select	c.415A>C	p.Met139Leu	missense	Exon 3 of 5	ENSP00000229335.6
	AICDA	ENST00000543081.6	TSL:1	c.415A>C	p.Met139Leu	missense	Exon 3 of 4	ENSP00000439103.2
	AICDA	ENST00000544516.6	TSL:1	c.157-890A>C		intron	N/A	ENSP00000439538.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461726 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727184

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44706

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53378

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5738

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111986

Other (OTH) AF: 0.00 AC: 0 AN: 60382

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.51	D
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D
M_CAP	Benign	0.076	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	0.21	D
MutationAssessor	Pathogenic	3.7	H
PhyloP100		7.4
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-2.7	D
REVEL	Uncertain	0.63
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.93	P
Vest4		0.85
MutPred		0.94		Loss of MoRF binding (P = 0.0924)
MVP		0.83
MPC		1.3
ClinPred		0.99	D
GERP RS		5.6
Varity_R		0.96
gMVP		0.81
Mutation Taster		=37/63	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs104894322; hg19: chr12-8757823;