2-138002077-G-T

Variant summary

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

The NM_006895.3(HNMT):c.312G>T(p.Lys104Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000883 in 1,585,946 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000070 ( 0 hom. )

Consequence

HNMT
NM_006895.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.610

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:

Genome browser will be placed here

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 (MetaRNN=0.06456444).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
HNMT	NM_006895.3 linkuse as main transcript	c.312G>T	p.Lys104Asn	missense_variant	4/6	ENST00000280097.5
HNMT	XM_017003948.2 linkuse as main transcript	c.210G>T	p.Lys70Asn	missense_variant	4/6
HNMT	XM_017003949.3 linkuse as main transcript	c.312G>T	p.Lys104Asn	missense_variant	4/5
HNMT	XM_011511064.3 linkuse as main transcript	c.-67G>T		5_prime_UTR_variant	3/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HNMT	ENST00000280097.5 linkuse as main transcript	c.312G>T	p.Lys104Asn	missense_variant	4/6	1	NM_006895.3	P1	P50135-1
HNMT	ENST00000410115.5 linkuse as main transcript	c.312G>T	p.Lys104Asn	missense_variant	5/7	5		P1	P50135-1
HNMT	ENST00000467390.5 linkuse as main transcript	n.324G>T		non_coding_transcript_exon_variant	4/5	2
HNMT	ENST00000485653.1 linkuse as main transcript	n.244G>T		non_coding_transcript_exon_variant	3/5	5

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152086

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:

0.000772

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000684

AC:

AN:

233932

Hom.:

AF XY:

0.0000632

AC XY:

AN XY:

126540

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000937

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000697

AC:

AN:

1433860

Hom.:

Cov.:

AF XY:

0.00000561

AC XY:

AN XY:

712568

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000257

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152086

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74286

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000772

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000264

ExAC

AF:

0.0000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 15, 2023

The c.312G>T (p.K104N) alteration is located in exon 4 (coding exon 4) of the HNMT gene. This alteration results from a G to T substitution at nucleotide position 312, causing the lysine (K) at amino acid position 104 to be replaced by an asparagine (N). 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

AlphaMissense

Benign

0.15

BayesDel_addAF

Benign

-0.49

BayesDel_noAF

Benign

-0.53

Cadd

Benign

Dann

Uncertain

1.0

DEOGEN2

Benign

0.066

T;T

Eigen

Uncertain

0.33

Eigen_PC

Uncertain

0.36

FATHMM_MKL

Uncertain

0.80

M_CAP

Benign

0.010

MetaRNN

Benign

0.065

T;T

MetaSVM

Benign

-0.99

MutationAssessor

Uncertain

2.3

M;M

MutationTaster

Benign

0.64

D;D

PrimateAI

Benign

0.42

PROVEAN

Benign

-1.2

N;N

REVEL

Benign

0.088

Sift

Uncertain

0.018

D;D

Sift4G

Benign

0.077

T;T

Polyphen

0.90

P;P

Vest4

0.21

MutPred

0.32

Loss of ubiquitination at K104 (P = 0.0071);Loss of ubiquitination at K104 (P = 0.0071);

MVP

0.59

MPC

0.075

ClinPred

0.17

GERP RS

4.2

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.46

gMVP

0.42

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