2-137981259-G-C

Variant names:

• chr2-137981259-G-C
• rs376421030
• ENST00000329366.8:c.234G>C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001024075.3(HNMT):​c.234G>C​(p.Ser78Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000132 in 151,596 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 31)
• Consequence: HNMT NM_001024075.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.19

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]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).
• BP7: Synonymous conserved (PhyloP=1.19 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HNMT	NM_006895.3	c.190+11042G>C		intron_variant	Intron 2 of 5	ENST00000280097.5	NP_008826.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HNMT	ENST00000280097.5	c.190+11042G>C		intron_variant	Intron 2 of 5	1	NM_006895.3	ENSP00000280097.3

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151596 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000485

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

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151596 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 73990

Gnomad4 AFR AF: 0.0000485

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

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.85
CADD	Benign	7.1
DANN	Benign	0.52

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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

Other links and lift over

dbSNP: rs376421030; hg19: chr2-138738829;