NM_000687.4:c.1223A>G

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4

The NM_000687.4(AHCY):​c.1223A>G​(p.Lys408Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,614,004 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K408M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

AHCY
NM_000687.4 missense

Scores

1
7
11

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.46

Publications

1 publications found
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 Gene-Disease associations (from GenCC):
  • hypermethioninemia with deficiency of S-adenosylhomocysteine hydrolase
    Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.41357124).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
AHCYNM_000687.4 linkc.1223A>G p.Lys408Arg missense_variant Exon 10 of 10 ENST00000217426.7 NP_000678.1 P23526-1A0A384MTQ3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
AHCYENST00000217426.7 linkc.1223A>G p.Lys408Arg missense_variant Exon 10 of 10 1 NM_000687.4 ENSP00000217426.2 P23526-1
AHCYENST00000538132.1 linkc.1139A>G p.Lys380Arg missense_variant Exon 10 of 10 2 ENSP00000442820.1 P23526-2
AHCYENST00000480653.5 linkn.1371A>G non_coding_transcript_exon_variant Exon 9 of 9 2
ENSG00000250917ENST00000512005.1 linkn.64A>G non_coding_transcript_exon_variant Exon 1 of 3 3

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152204
Hom.:
0
Cov.:
32
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
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251406
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000198
AC:
29
AN:
1461800
Hom.:
0
Cov.:
31
AF XY:
0.0000234
AC XY:
17
AN XY:
727198
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5706
European-Non Finnish (NFE)
AF:
0.0000216
AC:
24
AN:
1112010
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.499
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152204
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74348
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.600
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000581
Hom.:
0
Bravo
AF:
0.0000340
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

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
Mar 14, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 408 of the AHCY protein (p.Lys408Arg). This variant is present in population databases (rs373929711, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with AHCY-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available"). 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
Benign
0.070
BayesDel_addAF
Uncertain
0.051
T
BayesDel_noAF
Benign
-0.15
CADD
Benign
21
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.45
T;.
Eigen
Benign
0.097
Eigen_PC
Uncertain
0.25
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Uncertain
0.86
D;D
M_CAP
Benign
0.031
D
MetaRNN
Benign
0.41
T;T
MetaSVM
Benign
-0.46
T
MutationAssessor
Benign
1.6
L;.
PhyloP100
7.5
PrimateAI
Uncertain
0.65
T
PROVEAN
Benign
-1.7
N;N
REVEL
Uncertain
0.32
Sift
Benign
0.11
T;T
Sift4G
Benign
0.11
T;T
Polyphen
0.0040
B;.
Vest4
0.38
MVP
0.84
MPC
0.40
ClinPred
0.62
D
GERP RS
4.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.28
gMVP
0.55
Mutation Taster
=66/34
polymorphism

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

Other links and lift over

dbSNP: rs373929711; hg19: chr20-32868916; API