Rare Ophthalmology 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



Porencephaly is a rare condition that affects the central nervous system. People with porencephaly develop fluid-filled cysts or cavities in the brain either before or shortly after birth. The severity of the condition and the associated signs and symptoms vary significantly based on the size, location, and number of cysts. Common features include developmental delay, reduced muscle tone (hypotonia), seizures, macrocephaly (unusually large head size), spastic hemiplegia, speech problems, delayed growth, and intellectual disability. Porencephaly is usually the result of damage from infection or stroke after birth. In these cases, the condition occurs sporadically in people with no family history of the condition.[1][2] There is an inherited form of the condition called familial porencephaly, which is caused by changes (mutations) in the COL4A1 or COL4A2 genes and is inherited in an autosomal dominant manner.[3][4] Treatment is based on the signs and symptoms present in each person and may include physical therapy and medication for seizures.[1][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
Porencephalic cyst
Cavity within brain
Involuntary muscle stiffness, contraction, or spasm
30%-79% of people have these symptoms
Cerebral palsy
Paralysis or weakness of one side of body
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific

[ more ]


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.
  • Online Mendelian Inheritance in Man (OMIM) lists the subtypes and associated genes for Porencephaly in a table called Phenotypic Series. Each entry in OMIM includes 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 Porencephaly. Click on the link to view a sample search on this topic.


  1. NINDS Porencephaly Information Page. National Institute of Neurological Disorders and Stroke. June 2015; https://www.ninds.nih.gov/disorders/porencephaly/porencephaly.htm.
  2. Sporadic Porencephaly. NORD. 2013; https://rarediseases.org/rare-diseases/sporadic-porencephaly/.
  3. PORENCEPHALY 1. OMIM. February 2016; https://www.omim.org/entry/175780?search=porencephaly&highlight=porencephaly.
  4. PORENCEPHALY 2. OMIM. February 2012; https://www.omim.org/entry/614483?search=porencephaly&highlight=porencephaly.