Genetic Variant NAT8B:p.Arg149His (chr2-73700860-C-T) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The ENST00000377712.3(NAT8B):c.446G>A(p.Arg149His) variant causes a missense change. The variant allele was found at a frequency of 0.0000136 in 1,614,180 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 Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

NAT8B
ENST00000377712.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 5.09

Variant links:

Genes affected

NAT8B (HGNC:30235): (N-acetyltransferase 8B (putative, gene/pseudogene)) This gene is highly similar to the N-acetyltransferase 8 (NAT8) gene which encodes a kidney and liver protein with homology to bacterial acetyltransferases involved in drug resistance. This gene is localized on chromosome 2 in the vicinity of the NAT8 gene and represents a human-specific transcribed pseudogene of NAT8. This gene contains two common polymorphic nonsense mutations that disrupt the active site of the protein. In the extremely rare event when both nonsense mutations are absent, the predicted protein would contain a complete acetyltransferase domain and would be identical in length to NAT8. [provided by RefSeq, Apr 2022]

NAT8B links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.53).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NAT8B	NR_132338.2 link	n.653G>A		non_coding_transcript_exon_variant	Exon 2 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NAT8B	ENST00000377712.3 link	c.446G>A	p.Arg149His	missense_variant	Exon 1 of 1	6		ENSP00000485054.2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152168

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:

0.000192

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:

0.0000278

AC:

AN:

251454

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135910

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000272

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000137

AC:

AN:

1461894

Hom.:

Cov.:

106

AF XY:

0.00000963

AC XY:

AN XY:

727248

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000176

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000719

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152286

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000227

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Feb 26, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.446G>A (p.R149H) alteration is located in exon 1 (coding exon 1) of the NAT8B gene. This alteration results from a G to A substitution at nucleotide position 446, causing the arginine (R) at amino acid position 149 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.53

CADD

Uncertain

DANN

Benign

0.56

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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