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

Christianson syndrome



Other Names:
Intellectual disability x-linked syndromic Christianson type; MRXS Christianson; Angelman-like syndrome x-linked; Intellectual disability x-linked syndromic Christianson type; MRXS Christianson; Angelman-like syndrome x-linked; Intellectual disability microcephaly epilepsy and ataxia syndrome; X-linked Angelman-like syndrome; X-linked intellectual disability - craniofacial dysmorphism - epilepsy - ophthalmoplegia - cerebellar atrophy; X-linked intellectual disability, South African type; X-linked intellectual disability-craniofacial dysmorphism-epilepsy-ophthalmoplegia-cerebellar atrophy syndrome See More
Categories:

Christianson syndrome is an X-linked syndrome associated with intellectual disabilitymicrocephaly, seizures, ataxia, and absent speech.[1][2] Many individuals with this condition have a happy demeanor with frequent smiling and unprovoked laughter, similar to those with Angelman syndrome.[1] Christianson syndrome is caused by mutations in the SLC9A6 gene, which is located within the q24-q27 interval of the X chromosome.[1] There appears to be a range of phenotypes in carrier females, from intellectual disability to absence of symptoms.[1][2]
Last updated: 1/26/2015

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
Absent speech
Absent speech development
Lack of language development
Lack of speech
No speech development
No speech or language development
Nonverbal
[ more ]
0001344
Aplasia/Hypoplasia of the cerebellum
Absent/small cerebellum
Absent/underdeveloped cerebellum
[ more ]
0007360
Cachexia
Wasting syndrome
0004326
Cerebellar atrophy
Degeneration of cerebellum
0001272
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood
[ more ]
0002376
Generalized-onset seizure 0002197
Intellectual disability, profound
IQ less than 20
0002187
Long face
Elongation of face
Increased height of face
Increased length of face
Vertical elongation of face
Vertical enlargement of face
Vertical overgrowth of face
[ more ]
0000276
Macrotia
Large ears
0000400
Narrow face
Decreased breadth of face
Decreased width of face
[ more ]
0000275
Neuronal loss in central nervous system
Loss of brain cells
0002529
Severe global developmental delay 0011344
Strabismus
Cross-eyed
Squint
Squint eyes
[ more ]
0000486
Thick eyebrow
Bushy eyebrows
Dense eyebrow
Heavy eyebrows
Prominent eyebrows
Thick eyebrows
[ more ]
0000574
Truncal ataxia
Instability or lack of coordination of central trunk muscles
0002078
30%-79% of people have these symptoms
Adducted thumb
Inward turned thumb
0001181
Aplasia/Hypoplasia of the corpus callosum 0007370
Autism 0000717
Cerebral cortical atrophy
Decrease in size of the outer layer of the brain due to loss of brain cells
0002120
Conspicuously happy disposition 0100024
Dysphagia
Poor swallowing
Swallowing difficulties
Swallowing difficulty
[ more ]
0002015
Dystonia 0001332
Feeding difficulties in infancy 0008872
Gait ataxia
Inability to coordinate movements when walking
0002066
Gastroesophageal reflux
Acid reflux
Acid reflux disease
Heartburn
[ more ]
0002020
Inappropriate laughter 0000748
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference
[ more ]
0000252
Mutism
Inability to speak
Muteness
[ more ]
0002300
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
Ophthalmoplegia
Eye muscle paralysis
0000602
Pectus excavatum
Funnel chest
0000767
Stereotypy
Repetitive movements
Repetitive or self-injurious behavior
[ more ]
0000733
Ventriculomegaly 0002119
5%-29% of people have these symptoms
Abnormality of the nose
Nasal abnormality
0000366
Arthrogryposis multiplex congenita 0002804
Death in early adulthood 0100613
Decreased muscle mass 0003199
Deeply set eye
Deep set eye
Deep-set eyes
Sunken eye
[ more ]
0000490
Joint hyperflexibility
Joints move beyond expected range of motion
0005692
Mandibular prognathia
Big lower jaw
Increased projection of lower jaw
Increased size of lower jaw
Large lower jaw
Prominent chin
Prominent lower jaw
[ more ]
0000303
Percent of people who have these symptoms is not available through HPO
Abnormality of the foot
Abnormal feet morphology
Abnormality of the feet
Foot deformities
Foot deformity
[ more ]
0001760
Bowel incontinence
Loss of bowel control
0002607
Decreased body weight
Decreased weight
Low body weight
Low weight
Weight less than 3rd percentile
[ more ]
0004325
Drooling
Dribbling
0002307
Flexion contracture
Flexed joint that cannot be straightened
0001371
Generalized hypotonia
Decreased muscle tone
Low muscle tone
[ more ]
0001290
Global developmental delay 0001263
Happy demeanor 0040082
Hyperkinetic movements
Muscle spasms
0002487
Intellectual disability, progressive
Mental retardation, progressive
Progressive mental retardation
[ more ]
0006887
Intellectual disability, severe
Early and severe mental retardation
Mental retardation, severe
Severe mental retardation
[ more ]
0010864
Long nose
Elongated nose
Increased height of nose
Increased length of nose
Increased nasal height
Increased nasal length
Nasal elongation
[ more ]
0003189
Loss of ability to walk in first decade 0006794
Narrow chest
Low chest circumference
Narrow shoulders
[ more ]
0000774
Open mouth
Gaped jawed appearance
Gaped mouthed appearance
Slack jawed appearance
[ more ]
0000194
Photosensitive tonic-clonic seizure 0007207
Skeletal muscle atrophy
Muscle degeneration
Muscle wasting
[ more ]
0003202
Sleep disturbance
Difficulty sleeping
Trouble sleeping
[ more ]
0002360
Slender finger
Narrow fingers
Slender fingers
thin fingers
[ more ]
0001238
Urinary incontinence
Loss of bladder control
0000020
X-linked dominant inheritance 0001423
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Last updated: 7/1/2020

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnoses include Angelman syndrome, spinocerebellar ataxia type 29 (see these terms) and other X-linked forms of intellectual deficiencies.
Visit the Orphanet disease page for more information.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease


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

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • 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 Christianson syndrome. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • How many people have been diagnosed with Christianson syndrome? See answer



  1. Mental Retardation, X-Linked, Syndromic, Christianson Type. Online Mendelian Inheritance in Man (OMIM). February 24, 2015; http://omim.org/entry/300243. Accessed 12/21/2015.
  2. Gilfillan GD, Selmer KK, Roxrud I, Smith R, Kyllerman M, Eiklid K, Kroken M, Mattingsdal M, Egeland T, Stenmark H, Sjøholm H, Server A, Samuelsson L, Christianson A, Tarpey P, Whibley A, Stratton MR, Futreal PA, Teague J, Edkins S, Gecz J, Turner G, Raymond FL, Schwartz C, Stevenson RE, Undlien DE, Strømme P. Am J Hum Genet. 2008; http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2427207/?tool=pubmed. Accessed 1/6/2010.
  3. Intellectual deficit, X-linked, South African type. Orphanet. 2007; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=85278. Accessed 1/6/2010.