20-34281123-C-T

Variant summary

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

The NM_000687.4(AHCY):c.1210G>A(p.Val404Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000118 in 1,613,862 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00012 ( 0 hom. )

Consequence

AHCY
NM_000687.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.36

Variant links:

Genes affected

AHCY (HGNC:343): (adenosylhomocysteinase) S-adenosylhomocysteine hydrolase belongs to the adenosylhomocysteinase family. It catalyzes the reversible hydrolysis of S-adenosylhomocysteine (AdoHcy) to adenosine (Ado) and L-homocysteine (Hcy). Thus, it regulates the intracellular S-adenosylhomocysteine (SAH) concentration thought to be important for transmethylation reactions. Deficiency in this protein is one of the different causes of hypermethioninemia. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2009]

AHCY links:

(HGNC:):

links:

Genome browser will be placed here

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/exons	MANE	UniProt
AHCY	NM_000687.4 linkuse as main transcript	c.1210G>A	p.Val404Met	missense_variant	10/10	ENST00000217426.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AHCY	ENST00000217426.7 linkuse as main transcript	c.1210G>A	p.Val404Met	missense_variant	10/10	1	NM_000687.4	P1	P23526-1
	ENST00000512005.1 linkuse as main transcript	n.51G>A		non_coding_transcript_exon_variant	1/3	3
AHCY	ENST00000538132.1 linkuse as main transcript	c.1126G>A	p.Val376Met	missense_variant	10/10	2			P23526-2
AHCY	ENST00000480653.5 linkuse as main transcript	n.1358G>A		non_coding_transcript_exon_variant	9/9	2

Frequencies

GnomAD3 genomes

AF:

0.0000788

AC:

AN:

152220

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:

0.000176

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000756

AC:

AN:

251394

Hom.:

AF XY:

0.0000883

AC XY:

AN XY:

135870

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:

0.000167

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000122

AC:

178

AN:

1461642

Hom.:

Cov.:

AF XY:

0.000125

AC XY:

AN XY:

727124

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000156

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000788

AC:

AN:

152220

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74368

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:

0.000176

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000136

Hom.:

Bravo

AF:

0.0000831

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000349

AC:

ExAC

AF:

0.0000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Hypermethioninemia with deficiency of S-adenosylhomocysteine hydrolase

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 30, 2023

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 404 of the AHCY protein (p.Val404Met). This variant is present in population databases (rs147385277, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with AHCY-related conditions. ClinVar contains an entry for this variant (Variation ID: 2071752). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt AHCY protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.40

BayesDel_addAF

Uncertain

0.054

BayesDel_noAF

Uncertain

0.10

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Uncertain

0.55

D;.

Eigen

Uncertain

0.66

Eigen_PC

Uncertain

0.65

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.87

D;D

M_CAP

Uncertain

0.098

MetaRNN

Uncertain

0.64

D;D

MetaSVM

Uncertain

0.31

MutationAssessor

Pathogenic

3.4

M;.

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.77

PROVEAN

Benign

-2.0

N;N

REVEL

Pathogenic

0.70

Sift

Benign

0.051

T;T

Sift4G

Uncertain

0.041

D;D

Polyphen

0.88

P;.

Vest4

0.61

MVP

0.79

MPC

1.1

ClinPred

0.72

GERP RS

4.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.54

gMVP

0.87

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

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