AHDC1 encodes a nuclear protein whose loss of function causes Xia-Gibbs syndrome, a syndromic neurodevelopmental disorder marked by hypotonia, intellectual disability, developmental delay, and sleep apnea, arising via haploinsufficiency from de novo truncating mutations PMID:24791903. Wild-type AHDC1 localizes to the nucleus, and the C-terminal portion is required for correct nuclear targeting: patient-derived truncated proteins mislocalize, with short truncations distributing diffusely throughout the nucleus and mid-protein truncations aggregating in the nucleolus PMID:33644933. Beyond its neurodevelopmental role, AHDC1 acts as a regulator of energy metabolism, since Ahdc1-deficient mice develop obesity with reduced energy expenditure, hyperleptinemia, insulin resistance, and fatty liver PMID:37819197. The direct molecular mechanism by which nuclear AHDC1 influences gene regulation, development, or metabolism has not been characterized in the available corpus.
| Year | Confidence | Finding | PMIDs | Journal |
|---|---|---|---|---|
| 2014 | Medium | De novo truncating mutations in AHDC1 cause a syndromic neurodevelopmental disorder (Xia-Gibbs syndrome) characterized by hypotonia, intellectual disability, global developmental delay, and sleep apnea, establishing AHDC1 loss-of-function as causally pathogenic via haploinsufficiency. | PMID:24791903 | American journal of human genetics |
| 2021 | Medium | Wild-type AHDC1 protein localizes to the nucleus in human cell lines, while different patient-derived truncated forms show abnormal nuclear localization patterns: short truncated forms show diffuse nuclear distribution and mid-protein truncated forms aggregate in the nucleolus, indicating the C-terminal portion of AHDC1 is required for normal nuclear targeting. | PMID:33644933 | Human mutation |
| 2023 | Medium | Ahdc1 deficiency in mice (both male and female) causes obesity characterized by reduced energy expenditure and reduced respiratory quotient, with progressive hyperleptinemia, insulin resistance, abnormal glycolipid metabolism, and fatty liver, establishing AHDC1 as a regulator of energy metabolism. | PMID:37819197 | American journal of physiology. Endocrinology and metabolism |
| 2019 | Low | A rare mutation (c.-781C>G) in the 5'-UTR of AHDC1, identified in OSA patients with more severe clinical manifestations, was shown to affect AHDC1 expression levels. | PMID:31737670 | BioMed research international |
| 2022 | Low | In an individual with a large contiguous deletion encompassing AHDC1 and eight other genes, RNA expression analysis showed AHDC1 exhibited mono-allelic expression with no overall reduction in AHDC1 mRNA levels (unlike the other deleted genes which showed 50% reduction), suggesting a novel compensatory regulatory mechanism specifically for AHDC1 expression. | PMID:36054313 | Human mutation |
| 2019 | Low | AHDC1 haploinsufficiency (via microdeletion of ~575 Kb at 1p36.11 including AHDC1) causes Xia-Gibbs syndrome phenotypes, providing evidence that loss of a single functional copy of AHDC1 is sufficient to cause the disorder. | PMID:30615951 | European journal of medical genetics |