Genetic Variant HNMT:p.Gly62Asp (chr2-137970212-G-A) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_006895.3(HNMT):c.185G>A(p.Gly62Asp) variant causes a missense change. The variant allele was found at a frequency of 0.0000104 in 1,544,702 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 Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000043 ( 0 hom. )

Consequence

HNMT
NM_006895.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.93

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 Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.943

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HNMT	NM_006895.3 link	c.185G>A	p.Gly62Asp	missense_variant	Exon 2 of 6	ENST00000280097.5	NP_008826.1	P50135-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HNMT	ENST00000280097.5 link	c.185G>A	p.Gly62Asp	missense_variant	Exon 2 of 6	1	NM_006895.3	ENSP00000280097.3		P50135-1

Frequencies

GnomAD3 genomes

AF:

0.0000658

AC:

AN:

152088

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000242

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000207

AC:

AN:

241706

Hom.:

AF XY:

0.0000153

AC XY:

AN XY:

130672

show subpopulations

Gnomad AFR exome

AF:

0.000316

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000431

AC:

AN:

1392614

Hom.:

Cov.:

AF XY:

0.00000575

AC XY:

AN XY:

695836

show subpopulations

Gnomad4 AFR exome

AF:

0.000126

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:

0.00

Gnomad4 NFE exome

AF:

0.00000189

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000658

AC:

AN:

152088

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74288

show subpopulations

Gnomad4 AFR

AF:

0.000242

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000132

Hom.:

Bravo

AF:

0.0000831

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Oct 20, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.185G>A (p.G62D) alteration is located in exon 2 (coding exon 2) of the HNMT gene. This alteration results from a G to A substitution at nucleotide position 185, causing the glycine (G) at amino acid position 62 to be replaced by an aspartic acid (D). 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

Pathogenic

0.95

BayesDel_addAF

Pathogenic

0.17

BayesDel_noAF

Pathogenic

0.32

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.39

T;.;T

Eigen

Uncertain

0.49

Eigen_PC

Uncertain

0.39

FATHMM_MKL

Uncertain

0.89

LIST_S2

Benign

0.78

.;T;D

M_CAP

Pathogenic

0.49

MetaRNN

Pathogenic

0.94

D;D;D

MetaSVM

Uncertain

0.78

MutationAssessor

Pathogenic

3.1

M;M;M

PrimateAI

Uncertain

0.57

PROVEAN

Pathogenic

-6.3

D;D;D

REVEL

Pathogenic

0.90

Sift

Uncertain

0.0030

D;D;D

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

D;D;D

Vest4

0.88

MVP

0.97

MPC

0.43

ClinPred

0.81

GERP RS

4.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.0

Varity_R

0.89

gMVP

0.92

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