What is Xia-Gibbs syndrome?
Xia-Gibbs syndrome is a rare genetic syndrome associated mainly with intellectual disability.
This syndrome is also known as:
Mental Retardation, Autosomal Dominant 25; MRD25
What gene changes cause Xia-Gibbs syndrome?
Changes in the AHDC1 gene are responsible for causing the syndrome.
It is inherited in an autosomal dominant pattern, although all cases of the syndrome recorded so far have been the result of de novo or new mutations in the gene.
In the case of autosomal dominant inheritance, just one parent is the carrier of the gene mutation, and they have a 50% chance of passing it onto each of their children. Syndromes inherited in an autosomal dominant inheritance are caused by just one copy of the gene mutation.
In some cases, a genetic syndrome may be the result of a de-novo mutation and the first case in a family. In this case, this is a new gene mutation that occurs during the reproductive process.
What are the main symptoms of Xia-Gibbs syndrome?
The main symptoms of the syndrome include intellectual disability and developmental delay. This delay is more marked in speech development. Autistic traits have also been connected with the syndrome. There is also some evidence of brain defects in affected individuals.
Unique facial features associated with the syndrome include a broad forehead, widely spaced eyes, low-set ears that may also be larger than average, a flat nasal bridge, and a thin upper lip.
Sleep apnea, issues with breathing when asleep, is also common to the syndrome.
Other symptoms, especially in infancy, include a failure to thrive and low muscle tone.
Possible clinical traits/features:
Delayed myelination, Uplifted earlobe, Upslanted palpebral fissure, Retrocerebellar cyst, Intellectual disability, Micrognathia, Laryngomalacia, Muscular hypotonia, Low-set ears, Esotropia, Simplified gyral pattern, Depressed nasal bridge, Failure to thrive, Downslanted palpebral fissures, Obstructive sleep apnea, Hypoplasia of the corpus callosum, Hypertelorism, Global developmental delay.
How is it diagnosed?
To find out if someone has a diagnosis of Xia-Gibbs syndrome, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
