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Disease Profile

Diencephalic syndrome

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Diencephalic cachexia; Diencephalic syndrome of childhood; Diencephalic syndrome of emaciation;


Endocrine Diseases


Diencephalic syndrome is a condition caused by a tumor located in a portion of the brain above the brainstem called the diencephalon. The diencephalon includes the hypothalamus and the thalamus.[1] This condition is usually found in infants and young children and may result in symptoms including failure to gain weight and grow normally (failure to thrive), progressive thinness and weakness (emaciation), and hyperactivity and restlessness (hyperkinesia). Other symptoms may include abnormal eye movements and vision issues, vomiting, and hydrocephalus.[1][2][3] Diencephalic syndrome is most commonly caused by astrocytomas; however, other types of tumors may be associated including ependymoma, dysgerminoma, and ganglioma.[1][3] Given their location, these tumors may cause symptoms by leading to abnormal functioning of the hypothalamus and optic nerve.[3] Treatment usually involves surgery to remove as much of the tumor as possible, radiation therapy, and chemotherapy.[2]


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.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Abnormality of the hypothalamus-pituitary axis
Behavioral abnormality
Behavioral changes
Behavioral disorders
Behavioral disturbances
Behavioral problems
Behavioral/psychiatric abnormalities
Behavioural/Psychiatric abnormality
Psychiatric disorders
Psychiatric disturbances

[ more ]

Wasting syndrome
Neoplasm of the nervous system
Tumor of the nervous system
30%-79% of people have these symptoms
Abnormality of movement
Movement disorder
Unusual movement

[ more ]

Everted lower lip vermilion
Drooping lower lip
Outward turned lower lip

[ more ]

Too much cerebrospinal fluid in the brain
Excessive sweating
Increased sweating
Profuse sweating
Sweating profusely
Sweating, increased

[ more ]

Long penis
Enlarged penis
Large ears
Involuntary, rapid, rhythmic eye movements
5%-29% of people have these symptoms
Large hands
large hand
Optic atrophy


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

    Learn more

    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.
      • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.


        1. Paker RJ, Gilbert D, Gilbert J. Diencephalic Syndrome. National Organization for Rare Disorders (NORD). 2016; https://rarediseases.org/rare-diseases/diencephalic-syndrome/.
        2. Kim A, Moon JS, Yang HR, Chang JY, Ko JS, Seo JK. Diencephalic syndrome: a frequently neglected cause of failure to thrive in infants. Korean Journal of Pediatrics. January 2015; v.58(1):28-32. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4342778/.
        3. Cohen L. Diencephalic syndrome. Orphanet. October 2015; https://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=470&Disease_Disease_Search_diseaseGroup=Diencephalic-syndrome&Disease_Disease_Search_diseaseType=Pat&Disease(s)/group%20of%20diseases=Diencephalic-syndrome&title=Diencephalic-syndrome&search=Disease_Search_Simple.
        4. Diencephalic Syndrome. A Kids' Brain Tumor Cure PLGA Foundation. https://akidsbraintumorcure.org/childhood-brain-tumors/brain-tumor-treatment-options/complications/diencephalic-syndrome/. Accessed 4/27/2017.
        5. Kilday JP, Bartels U, Huang A, et al. Favorable survival and metabolic outcome for children with diencephalic syndrome using a radiation-sparing approach. J Neurooncol. January 2014; 116(1):195-204. https://www.ncbi.nlm.nih.gov/pubmed/24218181.