NM_000687.4:c.1170G>A

Variant names:

• chr20-34281163-C-T
• rs886056636
• NM_000687.4:c.1170G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000687.4(AHCY):​c.1170G>A​(p.Leu390Leu) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.000000685 in 1,460,824 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: AHCY NM_000687.4 splice_region, synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.51
• Publications: 0 publications found

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: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Orphanet

ENSG00000250917 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000687.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AHCY	NM_000687.4	MANE Select	c.1170G>A	p.Leu390Leu	splice_region synonymous	Exon 10 of 10	NP_000678.1	A0A384MTQ3
	AHCY	NM_001322086.2		c.1176G>A	p.Leu392Leu	splice_region synonymous	Exon 10 of 10	NP_001309015.1
	AHCY	NM_001362750.2		c.1170G>A	p.Leu390Leu	splice_region synonymous	Exon 10 of 11	NP_001349679.1	A0A384MTQ3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AHCY	ENST00000217426.7	TSL:1 MANE Select	c.1170G>A	p.Leu390Leu	splice_region synonymous	Exon 10 of 10	ENSP00000217426.2	P23526-1
	AHCY	ENST00000538132.1	TSL:2	c.1086G>A	p.Leu362Leu	splice_region synonymous	Exon 10 of 10	ENSP00000442820.1	P23526-2
	AHCY	ENST00000480653.5	TSL:2	n.1318G>A		splice_region non_coding_transcript_exon	Exon 9 of 9

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251048 AF XY: 0.00000737

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 6.85e-7 AC: 1 AN: 1460824 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726734

African (AFR) AF: 0.00 AC: 0 AN: 33446

American (AMR) AF: 0.00 AC: 0 AN: 44722

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: 86206

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53330

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5012

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111966

Other (OTH) AF: 0.0000166 AC: 1 AN: 60306

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Hypermethioninemia (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.15
CADD	Benign	22
DANN	Benign	0.94
PhyloP100		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.90		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.90		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs886056636; hg19: chr20-32868969;