NM_015909.4:c.1749G>A

Variant names:

• chr2-15468510-C-T
• rs770446752
• NM_015909.4:c.1749G>A

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_015909.4(NBAS):​c.1749G>A​(p.Trp583*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,742 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: NBAS NM_015909.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:3
• Conservation: PhyloP100: 7.91
• Publications: 4 publications found

Genes affected

NBAS (HGNC:15625): (NBAS subunit of NRZ tethering complex) This gene encodes a protein with two leucine zipper domains, a ribosomal protein S14 signature domain and a Sec39 like domain. The protein is thought to be involved in Golgi-to-ER transport. Mutations in this gene are associated with short stature, optic nerve atrophy, and Pelger-Huet anomaly. [provided by RefSeq, Oct 2012]

NBAS Gene-Disease associations (from GenCC):

• infantile liver failure syndrome 2

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P
• short stature-optic atrophy-Pelger-Huët anomaly syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Illumina, Labcorp Genetics (formerly Invitae), G2P

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-15468510-C-T is Pathogenic according to our data. Variant chr2-15468510-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 424842.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015909.4. 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
	NBAS	NM_015909.4	MANE Select	c.1749G>A	p.Trp583*	stop_gained	Exon 17 of 52	NP_056993.2
	NBAS	NR_052013.3		n.1779G>A		non_coding_transcript_exon	Exon 17 of 51

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NBAS	ENST00000281513.10	TSL:1 MANE Select	c.1749G>A	p.Trp583*	stop_gained	Exon 17 of 52	ENSP00000281513.5
	NBAS	ENST00000700066.1		c.1266G>A	p.Trp422*	stop_gained	Exon 15 of 22	ENSP00000514780.1
	NBAS	ENST00000700069.1		c.1620G>A	p.Trp540*	stop_gained	Exon 16 of 17	ENSP00000514781.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251226 AF XY: 0.0000221

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000342 AC: 5 AN: 1461742 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727168

African (AFR) AF: 0.00 AC: 0 AN: 33468

American (AMR) AF: 0.0000671 AC: 3 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39682

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111926

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, single submitter

Submissions by phenotype

Infantile liver failure syndrome 2 Pathogenic:1

Laboratory of Jean-Laurent Casanova, The Rockefeller University

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

not provided Pathogenic:1

Jun 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Trp583*) in the NBAS gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in NBAS are known to be pathogenic (PMID: 26073778, 26541327, 27789416, 28031453). This variant is present in population databases (rs770446752, gnomAD 0.006%). This premature translational stop signal has been observed in individual(s) with NBAS-related conditions (PMID: 28576691). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 424842). For these reasons, this variant has been classified as Pathogenic.

NBAS-related disorder Pathogenic:1

Oct 19, 2023

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The NBAS c.1749G>A variant is predicted to result in premature protein termination (p.Trp583*). This variant has been reported in the compound heterozygous state in two siblings with recurrent elevated liver transaminases and acute liver failure (Regateiro et al 2017. PubMed ID: 28576691). This variant is reported in 0.0058% of alleles in individuals of Latino descent in gnomAD (http://gnomad.broadinstitute.org/variant/2-15608634-C-T). Nonsense variants in NBAS are expected to be pathogenic. This variant is interpreted as pathogenic.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	40
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.9
Vest4		0.94
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/200	disease causing (ClinVar)

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: rs770446752; hg19: chr2-15608634;