NM_002485.5:c.2177A>C

Variant names:

• chr8-89943260-T-G
• rs1554555736
• NM_002485.5:c.2177A>C

Variant summary

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

The NM_002485.5(NBN):​c.2177A>C​(p.Glu726Ala) variant causes a missense change. 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: 5.28

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 rank	MANE	Protein	UniProt
NBN	NM_002485.5	c.2177A>C	p.Glu726Ala	missense_variant	Exon 14 of 16	ENST00000265433.8	NP_002476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8	c.2177A>C	p.Glu726Ala	missense_variant	Exon 14 of 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

Jan 11, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, this variant is a novel missense change with uncertain impact on protein function. 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: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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 glutamic acid with alanine at codon 726 of the NBN protein (p.Glu726Ala). The glutamic acid residue is moderately conserved and there is a moderate physicochemical difference between glutamic acid and alanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.67
BayesDel_addAF	Benign	0.0015	T
BayesDel_noAF	Benign	-0.24
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.22	T;T;.
Eigen	Uncertain	0.57
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.87	D;D;D
M_CAP	Benign	0.048	D
MetaRNN	Uncertain	0.53	D;D;D
MetaSVM	Benign	-0.61	T
MutationAssessor	Benign	1.3	L;.;.
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-2.2	N;N;.
REVEL	Benign	0.29
Sift	Benign	0.19	T;T;.
Sift4G	Benign	0.59	T;T;T
Polyphen		0.99	D;.;.
Vest4		0.63
MutPred		0.70		Loss of disorder (P = 0.035);.;.;
MVP		0.78
MPC		0.39
ClinPred		0.92	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.20
gMVP		0.32

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: rs1554555736; hg19: chr8-90955488;