AHCY

Chr 20AR

adenosylhomocysteinase

Also known as: SAHH, adoHcyase

NCBI Gene: 191ENSG00000101444UniProt: P23526OMIM: 180960

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]

OMIMResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

Hypermethioninemia with deficiency of S-adenosylhomocysteine hydrolaseMIM #613752
AR

Clinical highlights

Gene-disease validity (ClinGen)
hypermethioninemia with deficiency of S-adenosylhomocysteine hydrolase · ARDefinitivesufficient evidence for diagnostic panels
Interpreting a novel variant
This gene is strongly intolerant of loss-of-function variation in the population, so LoF variants warrant close attention. No curated mechanism annotation is available — see the mechanism card for the computational prediction and its caveats.Based on population constraint only.
0
Active trials
39
Pubs (1 yr)
—
P/LP submissions
—
P/LP missense
0.62
LOEUF
DN
Mechanism· predicted

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Tolerant — LoF & missense variants common in population
LoF Constraint?
0.62LOEUF
pLI 0.036
Z-score 2.79
OE 0.31 (0.17–0.62)
Tolerant

Typical tolerance to LoF variation

Missense Constraint?
1.55Z-score
OE missense 0.74 (0.66–0.83)
204 obs / 276.6 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?0.31 (0.17–0.62)
0≤0.351.4
Missense OE?0.74 (0.66–0.83)
0≤0.61.4
Synonymous OE?1.05
0≤1.21.6
LoF obs/exp: 6 / 19.2Missense obs/exp: 204 / 276.6Syn Z: -0.45

ClinVar Variant Classifications

0 submitted variants in ClinVar

ClinVar

Protein Context — Lollipop Plot

AHCY · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →

External Resources

Links to major genomics databases and tools

Franklin by Genoox
AI-powered variant curation and clinical analysis
DECIPHER
Genomic variants and phenotypes in rare disease patients