National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Xia-Gibbs syndrome


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Other Names:
AHDC1-related intellectual disability-obstructive sleep apnea-mild dysmorphism syndrome; Autosomal dominant intellectual disability 25
Categories:

Xia-Gibbs syndrome is a rare disorder of intellectual disability.[1][2][3] People with this syndrome usually present with developmental delay (especially delays in speech), low muscule tone (hypotonia), failure to thrive, mildly unusual facial  features (broad forehead, widely-spaced eyes (hypertelorism), big and low-set ears, flat nasal bridge, and thin upper lip), and breathing difficulties when sleeping (sleep apnea). The sleep apnea may be due to a collapse of the airway when breathing (tracheomalacia). Other signs and symptoms may include autistic features, seizures, lack of coordination (ataxia), behavioral problems, crossed-eyes (strabismus), and an abnormal lateral curvature of the spine (scoliosis).[1][4][3] Males usually have more severe symptoms than females. Brain MRI may show several structural brain defects, such as thinning of the corpus callosum and posterior fossa cysts.[1][4]

Xia-Gibbs syndrome is caused by variants (mutations) in the AHDC1 gene.[2] Inheritance is autosomal dominant but all reported cases to date have been due to new mutations (de novo), in individuals with no family history.[5][4][3] Treatment and management is supportive, and ideally, should involve several specialists. This may include careful monitoring of the airways, continuous positive airway pressure at night, frequent growth assessments, physical therapy and early interventions to maximize developmental potential.[4]

Last updated: 6/27/2018

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Global developmental delay 0001263
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ]
0001249
Muscular hypotonia
Low or weak muscle tone
0001252
30%-79% of people have these symptoms
Abnormal facial shape
Unusual facial appearance
0001999
Ataxia 0001251
Delayed ability to walk 0031936
Expressive language delay 0002474
Failure to thrive
Faltering weight
Weight faltering
[ more ]
0001508
Feeding difficulties
Feeding problems
Poor feeding
[ more ]
0011968
Joint laxity
Joint instability
Lax joints
Loose-jointedness
Loosejointedness
[ more ]
0001388
Obstructive sleep apnea 0002870
Seizure 0001250
Upbeat nystagmus 0011477
Upper airway obstruction 0002781
5%-29% of people have these symptoms
Autism 0000717
Cerebral visual impairment 0100704
Craniosynostosis 0001363
Deeply set eye
Deep set eye
Deep-set eyes
Sunken eye
[ more ]
0000490
Delayed myelination 0012448
Depressed nasal bridge
Depressed bridge of nose
Flat bridge of nose
Flat nasal bridge
Flat, nasal bridge
Flattened nasal bridge
Low nasal bridge
Low nasal root
[ more ]
0005280
Downslanted palpebral fissures
Downward slanting of the opening between the eyelids
0000494
EEG abnormality 0002353
Esotropia
Inward turning cross eyed
0000565
Hearing impairment
Deafness
Hearing defect
[ more ]
0000365
Hypertelorism
Wide-set eyes
Widely spaced eyes
[ more ]
0000316
Hypoplasia of the corpus callosum
Underdevelopment of part of brain called corpus callosum
0002079
Laryngomalacia
Softening of voice box tissue
0001601
Low-set ears
Low set ears
Lowset ears
[ more ]
0000369
Micrognathia
Little lower jaw
Small jaw
Small lower jaw
[ more ]
0000347
Mild myopia 0025573
Protruding ear
Prominent ear
Prominent ears
[ more ]
0000411
Respiratory failure requiring assisted ventilation 0004887
Retrocerebellar cyst 0006951
Scoliosis 0002650
Small earlobe
Small earlobes
0000385
Snoring 0025267
Tracheomalacia
Floppy windpipe
0002779
Uplifted earlobe
Lobe, uplifted
Upturned earlobe
[ more ]
0009909
Upslanted palpebral fissure
Upward slanting of the opening between the eyelids
0000582
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance 0000006
Generalized hypotonia
Decreased muscle tone
Low muscle tone
[ more ]
0001290
Simplified gyral pattern 0009879
Showing of 42 |
Last updated: 7/1/2020

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These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Xia-Gibbs syndrome. Click on the link to view a sample search on this topic.

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  1. Xia F, Bainbridge MN, Tan TY, et al. De Novo Truncating Mutations in AHDC1 in Individuals with Syndromic Expressive Language Delay, Hypotonia, and Sleep Apnea. American Journal of Human Genetics. 2014; 94(5):784-789. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4067559/.
  2. AHDC1 gene. Genetics Home Reference. 2018; https://ghr.nlm.nih.gov/gene/AHDC1.
  3. Yang H, Douglas G, Monaghan KG, et al. De novo truncating variants in the AHDC1 gene encoding the AT-hook DNA-binding motif-containing protein 1 are associated with intellectual disability and developmental delay. Cold Spring Harbor Molecular Case Studies. 2015; 1(1):https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4850891/.
  4. Jiang Y, Wangler MF, McGuire AL & cols. The phenotypic spectrum of Xia-Gibbs syndrome. Am J Med Genet A. June, 2018; 176(6):1315-1326. https://www.ncbi.nlm.nih.gov/pubmed/29696776.
  5. Xia-Gibbs syndrome. OMIM. 2014; https://www.omim.org/entry/615829.