chr8-89937024-A-C

Position:

chr8-89937024-A-C

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_002485.5(NBN):c.2234+2T>G variant causes a splice donor change. The variant allele was found at a frequency of 0.00000436 in 1,606,508 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

NBN
NM_002485.5 splice_donor

Scores

Splicing: ADA: 1.000

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 5.89

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.1, offset of 25, new splice context is: catGTacct. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PP5

Variant 8-89937024-A-C is Pathogenic according to our data. Variant chr8-89937024-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 185026.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NBN	NM_002485.5 linkuse as main transcript	c.2234+2T>G		splice_donor_variant		ENST00000265433.8	NP_002476.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NBN	ENST00000265433.8 linkuse as main transcript	c.2234+2T>G		splice_donor_variant		1	NM_002485.5	ENSP00000265433	P1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152226

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.00000801

AC:

AN:

249784

Hom.:

AF XY:

0.00000740

AC XY:

AN XY:

135044

show subpopulations

Gnomad AFR exome

AF:

0.00

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:

0.00000884

Gnomad OTH exome

AF:

0.000164

GnomAD4 exome

AF:

0.00000413

AC:

AN:

1454282

Hom.:

Cov.:

AF XY:

0.00000553

AC XY:

AN XY:

723910

show subpopulations

Gnomad4 AFR exome

AF:

0.0000300

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:

0.00000452

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152226

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74370

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000183

Hom.:

Bravo

AF:

0.00000378

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	May 08, 2017	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 15, 2023	Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Observed in individuals referred for hereditary cancer testing (LaDuca et al., 2017); This variant is associated with the following publications: (PMID: 23334666, 21035407, 17429352, 29922827, 24894818, 15964794, 15048089, 33804961, 28152038) -

Hereditary cancer-predisposing syndrome

Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 03, 2023	The c.2234+2T>G intronic variant results from a T to G substitution two nucleotides after coding exon 15 in the NBN gene. This alteration occurs at the 3' terminus of the NBN gene, is not expected to trigger nonsense-mediated mRNA decay, and only impacts the last 26 amino acids of the protein. The exact functional effect of this alteration is unknown; however, the impacted region is critical for protein function (Ambry internal data). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein. As such, this alteration is classified as likely pathogenic. -
Likely pathogenic, criteria provided, single submitter	curation	Sema4, Sema4	Mar 03, 2021	- -

Aplastic anemia

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Mar 27, 2024

- -

Microcephaly, normal intelligence and immunodeficiency

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 07, 2023

This sequence change affects a donor splice site in intron 15 of the NBN gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely disrupts the C-terminus of the protein. This variant is present in population databases (rs142301194, gnomAD 0.0009%). 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: 185026). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that disruption of this splice site results in skipping of exon 15 and introduces a new termination codon (Invitae). However the mRNA is not expected to undergo nonsense-mediated decay. This variant disrupts the ATM interaction domain of the NBN protein (PMID: 24894818, 21035407), which is important for activating ATM in the double-strand break repair pathway (PMID: 15964794, 15048089). While functional studies have not been performed to directly test the effect of this variant on NBN protein function, this suggests that disruption of this region of the protein is causative of disease. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.62

BayesDel_noAF

Pathogenic

0.27

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.88

FATHMM_MKL

Pathogenic

0.98

MutationTaster

Benign

1.0

D;D

GERP RS

5.1

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.91

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.91

Position offset: 2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over