8-89946142-T-C

Position:

• chr8-89946142-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_002485.5(NBN):​c.2068A>G​(p.Lys690Glu) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NBN NM_002485.5 missense, splice_region
• Scores: Splicing: ADA: 0.1802
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.69

Genes affected

NBN (HGNC:7652): (nibrin) Mutations in this gene are associated with Nijmegen breakage syndrome, an autosomal recessive chromosomal instability syndrome characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition. The encoded protein is a member of the MRE11/RAD50 double-strand break repair complex which consists of 5 proteins. This gene product is thought to be involved in DNA double-strand break repair and DNA damage-induced checkpoint activation. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.828

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NBN	NM_002485.5	c.2068A>G	p.Lys690Glu	missense_variant, splice_region_variant	13/16	ENST00000265433.8	NP_002476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8	c.2068A>G	p.Lys690Glu	missense_variant, splice_region_variant	13/16	1	NM_002485.5	ENSP00000265433	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Jan 06, 2021

This missense variant replaces lysine with glutamic acid at codon 690 of the NBN protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.42	T;T
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.77	T;T
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.83	D;D
MetaSVM	Uncertain	0.49	D
MutationAssessor	Uncertain	2.6	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-2.7	D;D
REVEL	Pathogenic	0.72
Sift	Uncertain	0.0030	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.83
MutPred		0.63		Loss of MoRF binding (P = 0.0032);.;
MVP		0.94
MPC		0.48
ClinPred		0.99	D
GERP RS		5.2
Varity_R		0.62
gMVP		0.67

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.18
dbscSNV1_RF	Benign	0.46
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

No publications associated with this variant yet.

Other links and lift over

hg19: chr8-90958370;