rs1060503472

Positions:

• chr8-89953626-G-C
• chr8-89953626-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_002485.5(NBN):​c.1463C>G​(p.Ser488Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,000 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S488Y) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NBN NM_002485.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 2.41

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.31351736).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NBN	NM_002485.5	c.1463C>G	p.Ser488Cys	missense_variant	11/16	ENST00000265433.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NBN	ENST00000265433.8	c.1463C>G	p.Ser488Cys	missense_variant	11/16	1	NM_002485.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461000 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726800

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: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

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	Labcorp Genetics (formerly Invitae), Labcorp	Jan 06, 2022	This variant is not present in population databases (gnomAD no frequency). This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 488 of the NBN protein (p.Ser488Cys). This variant has not been reported in the literature in individuals affected with NBN-related conditions. 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 411763). -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 14, 2021	- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 22, 2023

The p.S488C variant (also known as c.1463C>G), located in coding exon 11 of the NBN gene, results from a C to G substitution at nucleotide position 1463. The serine at codon 488 is replaced by cysteine, an amino acid with dissimilar properties. This variant was observed in an individual with early onset-breast cancer amongst a cohort of 1781 non-Ashkenazi Jewish individuals undergoing BRCA1/2 gene testing based on a personal history of breast cancer (Tung N et al. Cancer, 2015 Jan;121:25-33). 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	0.0074	T
BayesDel_noAF	Benign	-0.23
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Benign	0.35	T;T
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Benign	0.79	T;T
M_CAP	Benign	0.068	D
MetaRNN	Benign	0.31	T;T
MetaSVM	Benign	-0.28	T
MutationAssessor	Uncertain	2.7	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-2.2	N;N
REVEL	Benign	0.11
Sift	Uncertain	0.0080	D;D
Sift4G	Uncertain	0.015	D;D
Polyphen		1.0	D;.
Vest4		0.35
MutPred		0.25		Gain of catalytic residue at L489 (P = 0.0102);.;
MVP		0.85
MPC		0.35
ClinPred		0.96	D
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.16
gMVP		0.39

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: rs1060503472; hg19: chr8-90965854;