8-89980818-T-C

Variant names:

• chr8-89980818-T-C
• rs1060503462
• NM_002485.5:c.396A>G

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP6

The NM_002485.5(NBN):​c.396A>G​(p.Ile132Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,396 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I132V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NBN NM_002485.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: -0.0350
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 8-89980818-T-C is Benign according to our data. Variant chr8-89980818-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 411750.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002485.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NBN	NM_002485.5	MANE Select	c.396A>G	p.Ile132Met	missense	Exon 4 of 16	NP_002476.2
	NBN	NM_001024688.3		c.150A>G	p.Ile50Met	missense	Exon 5 of 17	NP_001019859.1
	NBN	NM_001440379.1		c.150A>G	p.Ile50Met	missense	Exon 4 of 16	NP_001427308.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NBN	ENST00000265433.8	TSL:1 MANE Select	c.396A>G	p.Ile132Met	missense	Exon 4 of 16	ENSP00000265433.4
	NBN	ENST00000697309.1		c.396A>G	p.Ile132Met	missense	Exon 4 of 15	ENSP00000513244.1
	NBN	ENST00000697293.1		c.396A>G	p.Ile132Met	missense	Exon 4 of 17	ENSP00000513230.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460396 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726592

African (AFR) AF: 0.00 AC: 0 AN: 33444

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39614

South Asian (SAS) AF: 0.00 AC: 0 AN: 86228

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53290

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110876

Other (OTH) AF: 0.0000166 AC: 1 AN: 60346

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

Asia WGS AF: 0.000289 AC: 1 AN: 3474

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Microcephaly, normal intelligence and immunodeficiency Uncertain:1 Benign:1

Nov 07, 2021

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Dec 04, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Uncertain:1

Apr 14, 2021

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Hereditary cancer-predisposing syndrome Uncertain:1

Aug 25, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.I132M variant (also known as c.396A>G), located in coding exon 4 of the NBN gene, results from an A to G substitution at nucleotide position 396. The isoleucine at codon 132 is replaced by methionine, an amino acid with highly similar properties. This amino acid position is poorly 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Uncertain	0.033	T
BayesDel_noAF	Benign	-0.19
CADD	Benign	17
DANN	Uncertain	0.99
DEOGEN2	Benign	0.17	T
Eigen	Benign	-0.30
Eigen_PC	Benign	-0.48
FATHMM_MKL	Benign	0.13	N
LIST_S2	Uncertain	0.86	D
M_CAP	Benign	0.043	D
MetaRNN	Uncertain	0.48	T
MetaSVM	Uncertain	-0.25	T
MutationAssessor	Benign	1.6	L
PhyloP100		-0.035
PrimateAI	Benign	0.30	T
PROVEAN	Benign	-1.7	N
REVEL	Uncertain	0.30
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.014	D
Polyphen		0.95	P
Vest4		0.54
MutPred		0.68		Gain of catalytic residue at I132 (P = 0.0107)
MVP		0.93
MPC		0.11
ClinPred		0.80	D
GERP RS		-4.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.18
gMVP		0.43
Mutation Taster		=86/14	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1060503462; hg19: chr8-90993046;