8-89984541-G-C

Variant names:

• chr8-89984541-G-C
• rs370050587
• NM_002485.5:c.21C>G

Variant summary

Our verdict is Benign. The variant received -11 ACMG points: 2P and 13B. PM2 BP4_Strong BP6_Very_Strong BP7

The NM_002485.5(NBN):​c.21C>G​(p.Ala7Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,460,802 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 Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. A7A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: NBN NM_002485.5 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: 0.377
• Publications: 1 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

ENSG00000309953 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -11 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.57).
• BP6: Variant 8-89984541-G-C is Benign according to our data. Variant chr8-89984541-G-C is described in ClinVar as Likely_benign. ClinVar VariationId is 383428.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.377 with no splicing effect.

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.21C>G	p.Ala7Ala	synonymous	Exon 1 of 16	NP_002476.2
	NBN	NM_001024688.3		c.-276C>G		5_prime_UTR	Exon 1 of 17	NP_001019859.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NBN	ENST00000265433.8	TSL:1 MANE Select	c.21C>G	p.Ala7Ala	synonymous	Exon 1 of 16	ENSP00000265433.4
	NBN	ENST00000697309.1		c.21C>G	p.Ala7Ala	synonymous	Exon 1 of 15	ENSP00000513244.1
	NBN	ENST00000697293.1		c.21C>G	p.Ala7Ala	synonymous	Exon 1 of 17	ENSP00000513230.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000122 AC: 3 AN: 245176 AF XY: 0.00000747

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000183

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1460802 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726760

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33448

American (AMR) AF: 0.00 AC: 0 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26116

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52852

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5722

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111724

Other (OTH) AF: 0.00 AC: 0 AN: 60296

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00955443), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:1

Jan 28, 2016

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease.

Microcephaly, normal intelligence and immunodeficiency Benign:1

Nov 03, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Hereditary cancer-predisposing syndrome Benign:1

Jun 08, 2016

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.57
CADD	Benign	3.9
DANN	Benign	0.59
PhyloP100		0.38
PromoterAI		-0.021	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.0

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

Other links and lift over

dbSNP: rs370050587; hg19: chr8-90996769;