rs1554555751

Positions:

• chr8-89943275-T-A

Variant summary

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

The ENST00000265433.8(NBN):​c.2162A>T​(p.Glu721Val) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. E721Q) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NBN ENST00000265433.8 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.72

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 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.2162A>T	p.Glu721Val	missense_variant	14/16	ENST00000265433.8	NP_002476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8	c.2162A>T	p.Glu721Val	missense_variant	14/16	1	NM_002485.5	ENSP00000265433	P1

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

Jul 13, 2017

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 do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with NBN-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamic acid with valine at codon 721 of the NBN protein (p.Glu721Val). The glutamic acid residue is moderately conserved and there is a moderate physicochemical difference between glutamic acid and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Benign	-0.055	T
BayesDel_noAF	Benign	-0.32
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.46	T;T;.
Eigen	Uncertain	0.54
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.88	D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Uncertain	0.54	D;D;D
MetaSVM	Benign	-0.35	T
MutationAssessor	Uncertain	2.3	M;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Benign	0.39	T
PROVEAN	Uncertain	-3.8	D;D;.
REVEL	Uncertain	0.37
Sift	Uncertain	0.0020	D;D;.
Sift4G	Uncertain	0.0020	D;D;D
Polyphen		0.95	P;.;.
Vest4		0.32
MutPred		0.69		Loss of disorder (P = 0.0043);.;.;
MVP		0.80
MPC		0.25
ClinPred		0.98	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.52
gMVP		0.36

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

LitVar

Other links and lift over

dbSNP: rs1554555751; hg19: chr8-90955503;