rs1555842652

Variant names:

• chr20-32806253-A-C
• rs1555842652
• NM_006892.4:c.2346A>C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_006892.4(DNMT3B):​c.2346A>C​(p.Lys782Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: DNMT3B NM_006892.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.50

Genes affected

DNMT3B (HGNC:2979): (DNA methyltransferase 3 beta) CpG methylation is an epigenetic modification that is important for embryonic development, imprinting, and X-chromosome inactivation. Studies in mice have demonstrated that DNA methylation is required for mammalian development. This gene encodes a DNA methyltransferase which is thought to function in de novo methylation, rather than maintenance methylation. The protein localizes primarily to the nucleus and its expression is developmentally regulated. Mutations in this gene cause the immunodeficiency-centromeric instability-facial anomalies (ICF) syndrome. Eight alternatively spliced transcript variants have been described. The full length sequences of variants 4 and 5 have not been determined. [provided by RefSeq, May 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a domain SAM-dependent MTase C5-type (size 278) in uniprot entity DNM3B_HUMAN there are 27 pathogenic changes around while only 1 benign (96%) in NM_006892.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the DNMT3B gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 15 curated pathogenic missense variants (we use a threshold of 10). The gene has 33 curated benign missense variants. Gene score misZ: 1.5 (below the threshold of 3.09). Trascript score misZ: 3.3234 (above the threshold of 3.09). GenCC associations: The gene is linked to immunodeficiency-centromeric instability-facial anomalies syndrome, immunodeficiency-centromeric instability-facial anomalies syndrome 1.
• BP4: Computational evidence support a benign effect (MetaRNN=0.24466735).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DNMT3B	NM_006892.4	c.2346A>C	p.Lys782Asn	missense_variant	Exon 22 of 23	ENST00000328111.6	NP_008823.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DNMT3B	ENST00000328111.6	c.2346A>C	p.Lys782Asn	missense_variant	Exon 22 of 23	1	NM_006892.4	ENSP00000328547.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Centromeric instability of chromosomes 1,9 and 16 and immunodeficiency Uncertain:1

Mar 06, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces lysine with asparagine at codon 782 of the DNMT3B protein (p.Lys782Asn). The lysine residue is weakly conserved and there is a moderate physicochemical difference between lysine and asparagine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with DNMT3B-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Benign	-0.016	T
BayesDel_noAF	Benign	-0.26
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.62	D;.;.
Eigen	Benign	0.093
Eigen_PC	Benign	0.20
FATHMM_MKL	Uncertain	0.83	D
LIST_S2	Uncertain	0.97	D;D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.24	T;T;T
MetaSVM	Uncertain	0.67	D
MutationAssessor	Uncertain	2.1	M;.;.
PrimateAI	Benign	0.48	T
PROVEAN	Uncertain	-3.5	D;D;D
REVEL	Uncertain	0.48
Sift	Uncertain	0.010	D;D;D
Sift4G	Uncertain	0.017	D;D;D
Polyphen		0.034	B;B;B
Vest4		0.25
MutPred		0.54		Loss of methylation at K782 (P = 8e-04);.;.;
MVP		0.92
MPC		0.97
ClinPred		0.97	D
GERP RS		4.3
Varity_R		0.81
gMVP		0.65

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: rs1555842652; hg19: chr20-31394059;