chr8-89947865-C-T

Position:

• chr8-89947865-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_002485.5(NBN):​c.1873G>A​(p.Glu625Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000771 in 1,426,258 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/23 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000077 (0 hom.)
• Consequence: NBN NM_002485.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 2.47

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.

• BP4: Computational evidence support a benign effect (MetaRNN=0.20434934).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NBN	NM_002485.5	c.1873G>A	p.Glu625Lys	missense_variant	12/16	ENST00000265433.8	NP_002476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8	c.1873G>A	p.Glu625Lys	missense_variant	12/16	1	NM_002485.5	ENSP00000265433	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000866 AC: 2 AN: 231004 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 124918

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000481

Gnomad NFE exome AF: 0.00000985

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000771 AC: 11 AN: 1426258 Hom.: 0 Cov.: 26 AF XY: 0.00000563 AC XY: 4 AN XY: 709986

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.000172

Gnomad4 NFE exome AF: 9.22e-7

Gnomad4 OTH exome AF: 0.0000170

GnomAD4 genome Cov.: 32

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Microcephaly, normal intelligence and immunodeficiency Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jul 12, 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 (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 and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with NBN-related disease. ClinVar contains an entry for this variant (Variation ID: 411774). This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamic acid with lysine at codon 625 of the NBN protein (p.Glu625Lys). The glutamic acid residue is moderately conserved and there is a small physicochemical difference between glutamic acid and lysine. -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Mar 30, 2018	- -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 02, 2023	The p.E625K variant (also known as c.1873G>A), located in coding exon 12 of the NBN gene, results from a G to A substitution at nucleotide position 1873. The glutamic acid at codon 625 is replaced by lysine, an amino acid with similar properties. This amino acid position is well 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Apr 10, 2019	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.084
BayesDel_addAF	Benign	-0.059	T
BayesDel_noAF	Benign	-0.32
CADD	Benign	20
DANN	Uncertain	1.0
DEOGEN2	Benign	0.15	T;T;.
Eigen	Benign	-0.29
Eigen_PC	Benign	-0.17
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Benign	0.76	T;T;T
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.20	T;T;T
MetaSVM	Benign	-0.89	T
MutationAssessor	Benign	1.9	L;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.51	T
PROVEAN	Benign	-1.3	N;N;.
REVEL	Benign	0.036
Sift	Uncertain	0.010	D;D;.
Sift4G	Benign	0.17	T;T;T
Polyphen		0.051	B;.;.
Vest4		0.48
MVP		0.74
MPC		0.078
ClinPred		0.29	T
GERP RS		5.1
Varity_R		0.14
gMVP		0.24

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.20		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.20		Position offset: 27

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs369049359; hg19: chr8-90960093;