Rare Gastroenterology 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.


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



Nervous System Diseases


Microcephaly is a rare neurological condition in which a person's head is significantly smaller than expected based on standardized charts. Some cases of microcephaly are detected at birth, while others develop in the first few years of life.[1][2] Some children with microcephaly have normal intelligence and development. However, microcephaly can be associated with seizures; developmental delay; intellectual disability; problems with movement and balance; feeding difficulties; hearing loss; and/or vision problems depending on the severity of the condition.[3] Because the growth of the skull is determined by brain growth, the condition often occurs when the brain fails to grow at a normal rate. This may be caused by a variety of genetic abnormalities; exposure to certain viruses (i.e. rubella, toxoplasmosis, and cytomegalovirus), drugs, alcohol, or toxic chemicals during pregnancy; untreated maternal PKU during pregnancy; and/or severe malnutrition during pregnancy.[2][3] Although there is no treatment for microcephaly, early intervention may help enhance development and improve quality of life.[4]


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

    • Boston Children's Hospital provides an information page on Microcephaly. Click on the link above to access this information.
    • You can obtain information on this topic from the Centers for Disease Control and Prevention (CDC). The CDC is recognized as the lead federal agency for developing and applying disease prevention and control, environmental health, and health promotion and education activities designed to improve the health of the people of the United States.
    • Mayo Clinic has an information page on Microcephaly.
    • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
    • The National Institute of Neurological Disorders and Stroke (NINDS) collects and disseminates research information related to neurological disorders. Click on the link to view information on this topic.

      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.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Microcephaly. Click on the link to view a sample search on this topic.


        1. Microcephaly. MedlinePlus. December 2013; https://www.nlm.nih.gov/medlineplus/ency/article/003272.htm.
        2. Microcephaly. Mayo Clinic. January 2016; https://www.mayoclinic.org/diseases-conditions/microcephaly/basics/definition/con-20034823.
        3. Facts about Microcephaly. Centers for Disease Control and Prevention. January 2016; https://www.cdc.gov/ncbddd/birthdefects/microcephaly.html.
        4. NINDS Microcephaly Information Page. National Institute of Neurological Disorders and Stroke (NINDS). June 2015; https://www.ninds.nih.gov/Disorders/All-Disorders/Microcephaly-Information-Page.