Genetic Variant HNMT:p.Glu109* (chr2-138002090-G-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_006895.3(HNMT):c.325G>T(p.Glu109*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000502 in 1,592,950 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

Frequency

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

Exomes 𝑓: 0.0000042 ( 0 hom. )

Consequence

HNMT
NM_006895.3 stop_gained

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.69

Variant links:

Genes affected

HNMT (HGNC:5028): (histamine N-methyltransferase) In mammals, histamine is metabolized by two major pathways: N(tau)-methylation via histamine N-methyltransferase and oxidative deamination via diamine oxidase. This gene encodes the first enzyme which is found in the cytosol and uses S-adenosyl-L-methionine as the methyl donor. In the mammalian brain, the neurotransmitter activity of histamine is controlled by N(tau)-methylation as diamine oxidase is not found in the central nervous system. A common genetic polymorphism affects the activity levels of this gene product in red blood cells. Multiple alternatively spliced transcript variants that encode different proteins have been found for this gene. [provided by RefSeq, Jul 2008]

HNMT links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HNMT	NM_006895.3 link	c.325G>T	p.Glu109*	stop_gained	Exon 4 of 6	ENST00000280097.5	NP_008826.1	P50135-1
HNMT	XM_017003948.2 link	c.223G>T	p.Glu75*	stop_gained	Exon 4 of 6		XP_016859437.1
HNMT	XM_017003949.3 link	c.325G>T	p.Glu109*	stop_gained	Exon 4 of 5		XP_016859438.1	B4DWC1
HNMT	XM_011511064.3 link	c.-54G>T		5_prime_UTR_variant	Exon 3 of 5		XP_011509366.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
HNMT	ENST00000280097.5 link	c.325G>T	p.Glu109*	stop_gained	Exon 4 of 6	1	NM_006895.3	ENSP00000280097.3	P50135-1
HNMT	ENST00000410115.5 link	c.325G>T	p.Glu109*	stop_gained	Exon 5 of 7	5		ENSP00000386940.1	P50135-1
HNMT	ENST00000467390.5 link	n.337G>T		non_coding_transcript_exon_variant	Exon 4 of 5	2
HNMT	ENST00000485653.1 link	n.257G>T		non_coding_transcript_exon_variant	Exon 3 of 5	5

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152022

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000125

AC:

AN:

239066

Hom.:

AF XY:

0.0000232

AC XY:

AN XY:

129264

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:

0.0000273

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000416

AC:

AN:

1440928

Hom.:

Cov.:

AF XY:

0.00000279

AC XY:

AN XY:

716212

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000123

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000453

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152022

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74244

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:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ExAC

AF:

0.0000247

AC:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.33

BayesDel_noAF

Pathogenic

0.30

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Uncertain

0.38

Eigen_PC

Benign

0.19

FATHMM_MKL

Uncertain

0.77

Vest4

0.83

GERP RS

3.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

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

Computational scores

Splicing

Publications

LitVar

Other links and lift over