8-89982718-A-G

Position:

• chr8-89982718-A-G

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_Strong BP6

The NM_002485.5(NBN):​c.171+4T>C variant causes a splice donor region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000174 in 1,611,986 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: NBN NM_002485.5 splice_donor_region, intron
• Scores: Splicing: ADA: 0.00007489
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:5
• Conservation: PhyloP100: 0.810

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 -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.71).
• BP6: Variant 8-89982718-A-G is Benign according to our data. Variant chr8-89982718-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 142185.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=5, Uncertain_significance=5}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NBN	NM_002485.5	c.171+4T>C		splice_donor_region_variant, intron_variant		ENST00000265433.8	NP_002476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8	c.171+4T>C		splice_donor_region_variant, intron_variant		1	NM_002485.5	ENSP00000265433	P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152224 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251390 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135874

Gnomad AFR exome AF: 0.0000615

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: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000178 AC: 26 AN: 1459762 Hom.: 0 Cov.: 29 AF XY: 0.0000207 AC XY: 15 AN XY: 726374

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: 0.0000216

Gnomad4 OTH exome AF: 0.0000332

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152224 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74356

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000565 Hom.: 0

Bravo AF: 0.0000264

EpiCase AF: 0.000109

EpiControl AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Microcephaly, normal intelligence and immunodeficiency Uncertain:3 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Mendelics	Jul 02, 2018	- -
Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 13, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Jan 25, 2017	- -

not provided Uncertain:1 Benign:2

Likely benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	Mar 17, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Dec 22, 2016	Variant summary: The NBN c.171+4T>C variant involves the alteration of a non-conserved intronic nucleotide. One in silico tool predicts a damaging outcome for this variant. 3/5 splice prediction tools predict strengthen effect on a canonical splicing donor site, and ESEfinder predicts change of binding site for SR055. However, these predictions have yet to be confirmed by functional studies. This variant was found in 3/121362 control chromosomes at a frequency of 0.0000247, which does not exceed the estimated maximal expected allele frequency of a pathogenic NBN variant (0.0025). In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as uncertain significance. The variant of interest has not, to our knowledge, been reported in affected individuals via publications; nor evaluated for functional impact by in vivo/vitro studies. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a variant of uncertain significance (VUS) until additional information becomes available. -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 08, 2019	This variant is associated with the following publications: (PMID: 29368341) -

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:2

Uncertain significance, criteria provided, single submitter	curation	Sema4, Sema4	Oct 08, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	May 21, 2021	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Likely benign, criteria provided, single submitter	clinical testing	Institute for Biomarker Research, Medical Diagnostic Laboratories, L.L.C.	Jun 11, 2024	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.71
CADD	Benign	12
DANN	Benign	0.77
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000075
dbscSNV1_RF	Benign	0.050
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: rs587782290; hg19: chr8-90994946;