Rare Pediatrics News

Disease Profile


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.

1-9 / 100 000

US Estimated

Europe Estimated

Age of onset

All ages





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)



Congenital and Genetic Diseases; Heart Diseases; Nervous System Diseases;


The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Orpha Number: 616

Medulloblastoma (MB) is an embryonic tumor of the neuroepithelial tissue and the most frequent primary pediatric solid malignancy. MB represents a heterogeneous group of cerebellar tumors characterized clinically by increased intracranial pressure and cerebellar dysfunction, with the most common presenting symptoms being headache, vomiting, and ataxia.

MB is the most common malignant brain tumor in childhood. Annual incidence is estimated at 1/909,000 in Europe. Males are more affected than females.

Clinical description
Age of disease onset is variable and can occur in patients ranging in age from the newborn period to adulthood (peak age at presentation is children 3-6 years, with only 25% of patients being between 15 and 44 years). The most common presenting symptoms are headache, vomiting, and ataxia. Additional features that may be observed include lethargy, motor or cranial nerve impairment, gaze palsy, visual impairment due to hydrocephalia, vertigo/hearing loss, behavioral changes/irritability, and extracranial pain (e.g. back pain in those with spinal metastases). Around 30% of pediatric cases present with metastases at diagnosis. Most metastases occur within the central nervous system by seeding via the cerebrospinal fluid (cranial or spinal), while spread to extracranial organs (e.g. bone marrow, liver, lungs) is very rare at diagnosis. In a minority of patients, MB is associated with Gorlin syndrome, familial adenomatous polyposis (FAP; the association of FAP and MB is referred to as the Turcot syndrome with polyposis) or with Li-Fraumeni Syndrome (see these terms). Increased susceptibility to certain tumors (neuroblastoma), hematological malignancies (acute lymphoblastic leukemia, acute myeloid leukemia) or disorders caused by mutations in genes encoding components of the RAS signaling pathway (Noonan syndrome or neurofibromatosis-Noonan syndrome) have been reported in MB (see these terms).

To date, the exact etiology of MB is still unknown but genomic data has identified multiple candidate genes that contribute to the pathogenesis of different subgroups of MB. This includes an inhibitor of the sonic hedgehog pathway SUFU (10q24.32), the RNA helicase DDX3X (Xp11.3-p11.23), chromatin regulators KDM6A (Xp11.2) and N-CoR complex genes BCOR (Xp11.4), and the Parkinson's disease genes KMT2D (12q13.12), SMARCA4 (19p13.3), MYCN (2p24.3), and TP53 (17p13.1).

Diagnostic methods
MB occurs in the vermis and 20% occurs in the hemispheres of the cerebellum. Histologically, MB is characterized by small, round cells that stain blue with haematoxylin spectrum and appearance ranges from tumors with extensive nodularity to those with large cell/anaplastic features. Apart from classical MB, four histological variants of MB are recognized: anaplastic MB, large cell MB, MB with extensive nodularity, and desmoplastic/nodular MB.

Differential diagnosis
Differential diagnosis includes other brain tumors (ependymoma, glial tumor, atypical teratoid rhabdoid tumor; see these terms) and other causes of cerebellar alterations (infectious or cystic lesions, hemorrhages).

Management and treatment
Initially, patients need to be checked for increased intracranial pressure, which if present, needs to be controlled either by drugs (e.g. steroids) or by neurosurgical drainage (e.g. external drainage). The postoperative treatment depends on age, histological variant, and result of staging assessments. In children older than 3-5 years, combinations of chemotherapy and craniospinal irradiation are applied. In younger children, brain sparing therapies avoiding irradiation can be administered in very specific constellations.

The overall survival rates are now 80% in standard risk patients, and 30-60 % in high-risk patients. Relapses occur in nearly 75% of pediatric cases within 2 years.

Visit the Orphanet disease page for more resources.


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:
30%-79% of people have these symptoms
Abnormal brain FDG positron emission tomography
Abnormal cranial nerve morphology
Cerebellar ataxia associated with quadrupedal gait
Cerebellar medulloblastoma
Delayed cranial suture closure
Lack of coordination of movement
Increased intracranial pressure
Rise in pressure inside skull
Intention tremor
Nausea and vomiting
Progressive cerebellar ataxia
Progressive macrocephaly
Progressively abnormally enlarging cranium
Progressively abnormally enlarging skull

[ more ]

5%-29% of people have these symptoms
Abnormality of bone marrow cell morphology
Adenomatous colonic polyposis
Back pain
Bilateral sensorineural hearing impairment
Cerebellar calcifications
Cerebellar cyst
Cerebellar hemorrhage
Cognitive impairment
Abnormality of cognition
Cognitive abnormality
Cognitive defects
Cognitive deficits
Intellectual impairment
Mental impairment

[ more ]

Double vision
Global developmental delay
Too much cerebrospinal fluid in the brain
Progressive visual loss
Progressive loss of vision
Progressive vision loss
Progressive visual impairment
Slowly progressive visual loss
Vision loss, progressive
Visual loss, progressive

[ more ]

Spinal cord tumor
Tumor of the spinal cord
Total ophthalmoplegia
Dizzy spell
1%-4% of people have these symptoms
Elevated hepatic transaminase
High liver enzymes
Neoplasm of the lung
Lung tumor
Cancer of early nerve cells
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
Autosomal recessive inheritance
Incomplete penetrance
Somatic mutation


Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.


    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

      • The National Cancer Institute provides the most current information on cancer for patients, health professionals, and the general public.

        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 Medulloblastoma. Click on the link to view a sample search on this topic.