8-89980829-T-G

Position:

• chr8-89980829-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_002485.5(NBN):​c.385A>C​(p.Asn129His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: NBN NM_002485.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.52

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]

NBN (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NBN	NM_002485.5	c.385A>C	p.Asn129His	missense_variant	4/16	ENST00000265433.8	NP_002476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8	c.385A>C	p.Asn129His	missense_variant	4/16	1	NM_002485.5	ENSP00000265433.4

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

Microcephaly, normal intelligence and immunodeficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 24, 2016

In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a NBN-related disease. This sequence change replaces asparagine with histidine at codon 129 of the NBN protein (p.Asn129His). The asparagine residue is moderately conserved and there is a small physicochemical difference between asparagine and histidine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.077
BayesDel_addAF	Benign	-0.028	T
BayesDel_noAF	Benign	-0.28
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Benign	0.23	T;T;.;.
Eigen	Uncertain	0.60
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Benign	0.74	D
LIST_S2	Benign	0.71	T;T;T;T
M_CAP	Benign	0.061	D
MetaRNN	Uncertain	0.65	D;D;D;D
MetaSVM	Uncertain	0.23	D
MutationAssessor	Benign	1.8	L;.;.;.
PrimateAI	Benign	0.32	T
PROVEAN	Uncertain	-2.7	D;D;D;D
REVEL	Benign	0.28
Sift	Uncertain	0.0050	D;D;T;D
Sift4G	Uncertain	0.018	D;D;.;D
Polyphen		1.0	D;.;.;.
Vest4		0.28
MutPred		0.70		Loss of catalytic residue at N129 (P = 0.0983);.;.;.;
MVP		0.94
MPC		0.083
ClinPred		0.92	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.30
gMVP		0.29

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs1060503477; hg19: chr8-90993057;