20-34281060-A-C

Position:

• chr20-34281060-A-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_000687.4(AHCY):​c.1273T>G​(p.Phe425Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: AHCY NM_000687.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.07

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 (HGNC:):

ACMG classification

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, 0.953

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AHCY	NM_000687.4	c.1273T>G	p.Phe425Val	missense_variant	10/10	ENST00000217426.7	NP_000678.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AHCY	ENST00000217426.7	c.1273T>G	p.Phe425Val	missense_variant	10/10	1	NM_000687.4	ENSP00000217426.2
AHCY	ENST00000538132.1	c.1189T>G	p.Phe397Val	missense_variant	10/10	2		ENSP00000442820.1
AHCY	ENST00000480653.5	n.1421T>G		non_coding_transcript_exon_variant	9/9	2
ENSG00000250917	ENST00000512005.1	n.114T>G		non_coding_transcript_exon_variant	1/3	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 08, 2019

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.71
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.76	D;.
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.95	D;D
MetaSVM	Uncertain	0.73	D
MutationAssessor	Pathogenic	4.1	H;.
PrimateAI	Uncertain	0.56	T
PROVEAN	Pathogenic	-5.0	D;D
REVEL	Pathogenic	0.92
Sift	Uncertain	0.0010	D;D
Sift4G	Pathogenic	0.0010	D;D
Polyphen		0.99	D;.
Vest4		0.73
MutPred		0.85		Gain of ubiquitination at K426 (P = 0.1586);.;
MVP		0.91
MPC		1.5
ClinPred		1.0	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.90
gMVP		0.90

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

Other links and lift over

dbSNP: rs1555830638; hg19: chr20-32868866;