rs587781939

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_002485.5(NBN):c.52C>A(p.Leu18Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000806 in 1,613,318 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. L18L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

NBN
NM_002485.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 3.83

Publications

2 publications found

Variant links:

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 Gene-Disease associations (from GenCC):

Nijmegen breakage syndrome
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, Myriad Women’s Health
rhabdomyosarcoma
Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
idiopathic aplastic anemia
Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
prostate cancer
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
hereditary breast carcinoma
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

NBN links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.22601774).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NBN	NM_002485.5 link	c.52C>A	p.Leu18Ile	missense_variant	Exon 2 of 16	ENST00000265433.8	NP_002476.2	O60934

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8 link	c.52C>A	p.Leu18Ile	missense_variant	Exon 2 of 16	1	NM_002485.5	ENSP00000265433.4		O60934

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152110

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000796

AC:

AN:

251306

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461208

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726938

show subpopulations

African (AFR)

AF:

0.000209

AC:

AN:

33450

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26124

East Asian (EAS)

AF:

0.00

AC:

AN:

39656

South Asian (SAS)

AF:

0.00

AC:

AN:

86232

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53326

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111560

Other (OTH)

AF:

0.00

AC:

AN:

60372

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.446

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152110

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74316

show subpopulations

African (AFR)

AF:

0.000145

AC:

AN:

41402

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5200

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10598

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68016

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000991

Hom.:

Bravo

AF:

0.0000642

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Microcephaly, normal intelligence and immunodeficiency

Uncertain:3

Jul 29, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jul 08, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 18 of the NBN protein (p.Leu18Ile). This variant is present in population databases (rs587781939, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with NBN-related conditions. ClinVar contains an entry for this variant (Variation ID: 141689). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

Nov 07, 2021

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Uncertain:1

Jan 29, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: NBN c.52C>A (p.Leu18Ile) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251306 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.52C>A has been reported in the literature in individuals affected with breast cancer or acute lymphoblastic leukemia (George_2021, Escherich_2024). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. At least one publication reports experimental evidence evaluating an impact on protein function. These results showed no damaging effect of this variant (Escherich_2024). The following publications have been ascertained in the context of this evaluation (PMID: 38446568, 33646313). ClinVar contains an entry for this variant (Variation ID: 141689). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Aplastic anemia

Uncertain:1

Dec 17, 2023

Baylor Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Uncertain:1

Feb 14, 2020

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Hereditary cancer-predisposing syndrome

Uncertain:1

Mar 01, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.L18I variant (also known as c.52C>A), located in coding exon 2 of the NBN gene, results from a C to A substitution at nucleotide position 52. The leucine at codon 18 is replaced by isoleucine, an amino acid with highly similar properties. This variant was identified in an individual from Barbados who was diagnosed with breast cancer at age 39 (George SHL et al. JAMA Netw Open, 2021 Mar;4:e210307). This amino acid position is highly 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

0.11

BayesDel_addAF

Benign

-0.36

BayesDel_noAF

Benign

-0.46

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.16

T;.

Eigen

Uncertain

0.25

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Uncertain

0.86

LIST_S2

Benign

0.81

T;T

M_CAP

Benign

0.016

MetaRNN

Benign

0.23

T;T

MetaSVM

Benign

-0.99

MutationAssessor

Benign

1.9

M;.

PhyloP100

3.8

PrimateAI

Uncertain

0.71

PROVEAN

Benign

-1.2

N;N

REVEL

Benign

0.16

Sift

Benign

0.072

T;T

Sift4G

Benign

0.12

T;T

Polyphen

0.98

D;.

Vest4

0.40

MVP

0.61

MPC

0.34

ClinPred

0.46

GERP RS

5.1

Varity_R

0.19

gMVP

0.45

Mutation Taster

=87/13

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over