NM_002485.5:c.47A>C

Variant names:

• chr8-89982846-T-G
• rs864622726
• NM_002485.5:c.47A>C

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_002485.5(NBN):​c.47A>C​(p.Tyr16Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict 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. Y16C) has been classified 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: 0.376
• 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
• BP4: Computational evidence support a benign effect (MetaRNN=0.31619412).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NBN	NM_002485.5	c.47A>C	p.Tyr16Ser	missense_variant	Exon 2 of 16	ENST00000265433.8	NP_002476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8	c.47A>C	p.Tyr16Ser	missense_variant	Exon 2 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

Jun 17, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine with serine at codon 16 of the NBN protein (p.Tyr16Ser). The tyrosine residue is moderately conserved and there is a large physicochemical difference between tyrosine and serine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature. 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. In summary, this is a novel missense change that is not predicted to affect protein function or cause disease. However the evidence is insufficient at this time to prove that conclusively. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Benign	-0.063	T
BayesDel_noAF	Benign	-0.33
CADD	Benign	20
DANN	Benign	0.93
DEOGEN2	Benign	0.37	T;.
Eigen	Benign	-0.23
Eigen_PC	Benign	-0.25
FATHMM_MKL	Benign	0.75	D
LIST_S2	Uncertain	0.87	D;T
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.32	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.9	M;.
PhyloP100		0.38
PrimateAI	Benign	0.46	T
PROVEAN	Uncertain	-4.0	D;D
REVEL	Benign	0.13
Sift	Uncertain	0.010	D;D
Sift4G	Uncertain	0.059	T;T
Polyphen		0.55	P;.
Vest4		0.58
MutPred		0.67		Gain of disorder (P = 0.0073);Gain of disorder (P = 0.0073);
MVP		0.56
MPC		0.15
ClinPred		0.40	T
GERP RS		0.76
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.26
gMVP		0.67
Mutation Taster		=91/9	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: rs864622726; hg19: chr8-90995074;