20-34278756-C-G

Variant names:

• chr20-34278756-C-G
• rs819173
• ENST00000512005.1:n.147+2271G>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The ENST00000512005.1(ENSG00000250917):​n.147+2271G>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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: not found (cov: 30)
• Consequence: ENSG00000250917 ENST00000512005.1 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.118
• Publications: 7 publications found

Genes affected

ENSG00000250917 (HGNC:):

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

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.71).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AHCY	XM_017027709.3	c.*8-587G>C		intron_variant	Intron 10 of 10		XP_016883198.1
AHCY	XM_047439962.1	c.*7+2271G>C		intron_variant	Intron 10 of 10		XP_047295918.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ENSG00000250917	ENST00000512005.1	n.147+2271G>C		intron_variant	Intron 1 of 2	3

Frequencies

GnomAD3 genomes Cov.: 30

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 30

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.71
CADD	Benign	8.3
DANN	Benign	0.86
PhyloP100		0.12

Splicing

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

Other links and lift over

dbSNP: rs819173; hg19: chr20-32866562;