HDAC8

Chr XXLD

histone deacetylase 8

Histone deacetylase that catalyzes the deacetylation of lysine residues on the N-terminal part of the core histones (H2A, H2B, H3 and H4) (PubMed:10748112, PubMed:10922473, PubMed:10926844, PubMed:14701748, PubMed:28497810). Histone deacetylation gives a tag for epigenetic repression and plays an important role in transcriptional regulation, cell cycle progression and developmental events (PubMed:10748112, PubMed:10922473, PubMed:10926844, PubMed:14701748). Histone deacetylases act via the formation of large multiprotein complexes (PubMed:10748112, PubMed:10922473, PubMed:10926844, PubMed:14701748). Also involved in the deacetylation of cohesin complex protein SMC3 regulating release of cohesin complexes from chromatin (PubMed:22885700). May play a role in smooth muscle cell contractility (PubMed:15772115). In addition to protein deacetylase activity, also has protein-lysine deacylase activity: acts as a protein decrotonylase by mediating decrotonylation ((2E)-butenoyl) of histones (PubMed:28497810)

Primary Disease Associations & Inheritance

Cornelia de Lange syndrome 5MIM #300882

XLD

434

ClinVar variants

136

Pathogenic / LP

0.98

pLI score· haploinsufficient

Active trials

Clinical Summary— HDAC8

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Gene-Disease Validity (ClinGen)

Cornelia de Lange syndrome · XLDefinitive

Definitive — sufficient evidence for diagnostic panels

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Population Constraint (gnomAD)

Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 0.98). One damaged copy is likely sufficient to cause disease.

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ClinVar Variants

136 Pathogenic / Likely Pathogenic· 125 VUS of 434 total submissions

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Clinical Trials

1 active or recruiting trial — potential therapeutic options may be available

Some data sources returned errors (1)

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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

LoF intolerant — likely haploinsufficient

LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.

0.30LOEUF

pLI 0.977

Z-score 3.47

OE 0.06 (0.02–0.30)

Highly constrained

Highly LoF-intolerant (top ~10% of genes)

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.

2.82Z-score

OE missense 0.35 (0.28–0.44)

51 obs / 147.4 exp

Mild constraint

Moderately missense-constrained (top ~2.5%)

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.

LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.06 (0.02–0.30)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.35 (0.28–0.44)

0≤0.61.4

Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.0.94

0≤1.21.6

LoF obs/exp: 1 / 16.0Missense obs/exp: 51 / 147.4Syn Z: 0.34