rs759315662

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_015909.4(NBAS):c.686_687insT(p.Ser230GlnfsTer4) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000244 in 1,613,722 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.00035 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00023 ( 0 hom. )

Consequence

NBAS
NM_015909.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 9.10

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 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 2-15534602-G-GA is Pathogenic according to our data. Variant chr2-15534602-G-GA is described in ClinVar as [Pathogenic]. Clinvar id is 204581.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NBAS	NM_015909.4 linkuse as main transcript	c.686_687insT	p.Ser230GlnfsTer4	frameshift_variant	9/52	ENST00000281513.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NBAS	ENST00000281513.10 linkuse as main transcript	c.686_687insT	p.Ser230GlnfsTer4	frameshift_variant	9/52	1	NM_015909.4	P1	A2RRP1-1

Frequencies

GnomAD3 genomes

AF:

0.000355

AC:

AN:

152166

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00141

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000559

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000350

AC:

AN:

251404

Hom.:

AF XY:

0.000339

AC XY:

AN XY:

135874

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:

0.00111

Gnomad NFE exome

AF:

0.000528

Gnomad OTH exome

AF:

0.000652

GnomAD4 exome

AF:

0.000232

AC:

339

AN:

1461556

Hom.:

Cov.:

AF XY:

0.000226

AC XY:

164

AN XY:

727112

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

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:

0.00148

Gnomad4 NFE exome

AF:

0.000214

Gnomad4 OTH exome

AF:

0.000348

GnomAD4 genome

AF:

0.000355

AC:

AN:

152166

Hom.:

Cov.:

AF XY:

0.000498

AC XY:

AN XY:

74342

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00141

Gnomad4 NFE

AF:

0.000559

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000453

Hom.:

Bravo

AF:

0.000147

EpiCase

AF:

0.000218

EpiControl

AF:

0.000119

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 13, 2017	The c.686dupT pathogenic variant in the NBAS gene has been reported previously in combination with another NBAS variant in at least two individuals with features of NBAS-related disorder, including early onset recurrent acute liver failure and short stature (Haack et al., 2015; Staufner et al., 2016). The c.686dupT variant causes a frameshift starting with codon Serine 230, changes this amino acid to a Glutamine residue, and creates a premature Stop codon at position 4 of the new reading frame, denoted p.Ser230GlnfsX4. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The c.686dupT variant is observed in 10/6,614 (0.15%) alleles from individuals of Finnish background in the ExAC dataset (Lek et al., 2016). We interpret c.686dupT as a pathogenic variant. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 25, 2024	This sequence change creates a premature translational stop signal (p.Ser230Glnfs*4) 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 (rs759315662, gnomAD 0.1%). This premature translational stop signal has been observed in individuals with clinical features of SPOH syndrome (PMID: 26073778). ClinVar contains an entry for this variant (Variation ID: 204581). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Mar 01, 2022	- -

Infantile liver failure syndrome 2

Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Jul 02, 2015	- -
Pathogenic, no assertion criteria provided	clinical testing	Laboratory of Medical Genetics, University of Torino	Nov 07, 2018	Found in compound heterozygosity with c.6840G>A -

Acute infantile liver failure due to synthesis defect of mtDNA-encoded proteins

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Nov 05, 2022

Variant summary: NBAS c.686dupT (p.Ser230GlnfsX4) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic within ClinVar (e.g. c.1213C>T [p.Arg405Ter], c.1987C>T [p.Gln663Ter]). The variant allele was found at a frequency of 0.00041 in 282794 control chromosomes (gnomAD). This frequency is not significantly higher than expected for a pathogenic variant in NBAS causing Liver Failure Acute Infantile, Type 2 (0.00041 vs 0.0011), allowing no conclusion about variant significance. c.686dupT has been reported in the literature as a biallelic genotype in individuals affected with Recurrant Acute Liver Failture (e.g. Haack_2015, Baldridge_2017, Carli_2019). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Six ClinVar submitters have assessed the variant since 2014: all classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

NBAS-related condition

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 11, 2023

The NBAS c.686dupT variant is predicted to result in a frameshift and premature protein termination (p.Ser230Glnfs*4). This variant has been reported in the compound heterozygous state in two unrelated individuals with acute liver failure (Families 1 and 10, Haack et al. 2015. PubMed ID: 26073778), and a third individual with hepatic, skeletal, ocular, and immunologic features, as well as dysmorphic facies (Patient 2, Carli et al. 2019. PubMed ID: 30825388). This variant is reported in 0.12% of alleles in individuals of European (Finnish) descent in gnomAD. Frameshift variants in NBAS are expected to be pathogenic. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

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