8-89971247-C-G

Position:

• chr8-89971247-C-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_002485.5(NBN):​c.628G>C​(p.Val210Leu) 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. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V210F) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: NBN NM_002485.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.408

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.028203249).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NBN	NM_002485.5	c.628G>C	p.Val210Leu	missense_variant	6/16	ENST00000265433.8	NP_002476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8	c.628G>C	p.Val210Leu	missense_variant	6/16	1	NM_002485.5	ENSP00000265433	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Microcephaly, normal intelligence and immunodeficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 13, 2022

This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 210 of the NBN protein (p.Val210Leu). 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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The leucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 826300). This variant has not been reported in the literature in individuals affected with NBN-related conditions. This variant is not present in population databases (gnomAD no frequency). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 28, 2024

The p.V210L variant (also known as c.628G>C), located in coding exon 6 of the NBN gene, results from a G to C substitution at nucleotide position 628. The valine at codon 210 is replaced by leucine, an amino acid with highly similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.47
CADD	Benign	4.3
DANN	Benign	0.83
DEOGEN2	Benign	0.058	T;T;.;.
Eigen	Benign	-1.1
Eigen_PC	Benign	-0.98
FATHMM_MKL	Benign	0.030	N
LIST_S2	Benign	0.77	T;T;T;T
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.028	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.46	N;.;.;.
MutationTaster	Benign	0.97	N;N
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-0.61	N;N;N;N
REVEL	Benign	0.041
Sift	Benign	0.48	T;T;T;T
Sift4G	Benign	0.71	T;T;T;.
Polyphen		0.0	B;.;.;.
Vest4		0.059
MutPred		0.24		Gain of catalytic residue at V210 (P = 0.0407);.;.;.;
MVP		0.71
MPC		0.066
ClinPred		0.14	T
GERP RS		-1.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.031
gMVP		0.41

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: rs61754796; hg19: chr8-90983475;