12-8605227-T-G

Variant names:

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

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 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 Likely 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

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a chain Single-stranded DNA cytosine deaminase (size 197) in uniprot entity AICDA_HUMAN there are 7 pathogenic changes around while only 1 benign (88%) in NM_020661.4
• 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 Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.978

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AICDA	NM_020661.4	c.415A>C	p.Met139Leu	missense_variant	Exon 3 of 5	ENST00000229335.11	NP_065712.1
AICDA	NM_001330343.2	c.415A>C	p.Met139Leu	missense_variant	Exon 3 of 5		NP_001317272.1
AICDA	NM_001410970.1	c.415A>C	p.Met139Leu	missense_variant	Exon 3 of 4		NP_001397899.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AICDA	ENST00000229335.11	c.415A>C	p.Met139Leu	missense_variant	Exon 3 of 5	1	NM_020661.4	ENSP00000229335.6

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

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

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;D
M_CAP	Benign	0.076	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Uncertain	0.21	D
MutationAssessor	Pathogenic	3.7	H;H
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-2.7	D;D
REVEL	Uncertain	0.63
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		0.93	P;.
Vest4		0.85
MutPred		0.94		Loss of MoRF binding (P = 0.0924);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

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-8757823;