X-linked periventricular heterotopia

What causes X-linked periventricular heterotopia?

X-linked periventricular heterotopia is caused by mutations in the FLNA gene. This gene provides instructions for making the protein filamin A, which helps build the network of protein that gives structure to cells and allows them to change shape and move (cytoskeleton). Certain mutations in the FLNA gene result in an impaired filamin A protein that cannot perform this function, leading to a disruption of the normal migration patterns of neurons during brain development.

Last updated on 05-01-20

How is X-linked periventricular heterotopia inherited?

Inheritance of X-linked periventricular heterotopia is X-linked dominant. This means that the gene responsible for the condition is located on the X chromosome, and having only one mutated copy of the gene is enough to cause the condition.

Because males have only one X chromosome (and one Y chromosome) and females have two X chromosomes, X-linked dominant conditions affect males and females differently. Both males and females can have an X-linked dominant condition. However, because males don't have a second, working copy of the gene (as females do), they usually have more severe disease than females.

In rare cases, males with FLNA mutations survive to adulthood and father children. If a father has the mutated X-linked gene:

  • all of his daughters will inherit the mutated gene (they will all receive his X chromosome)
  • none of his sons will inherit the mutated gene (they only inherit his Y chromosome)

If a mother has the mutated X-linked gene, each of her children (both male and female) has a 50% chance to inherit the mutated gene.

In about 50 percent of cases of X-linked periventricular heterotopia, an affected person inherits the mutation from a mother who is also affected. Other cases may result from new mutations in the gene (de novo). These cases occur in people with no history of the disorder in their family.

Last updated on 05-01-20

What is X-linked periventricular heterotopia?

X-linked periventricular heterotopia* or FLNA* -related periventricular nodular heterotopia** is a genetic disorder in which nerve cells in the brain do not migrate properly during early fetal development (a neuronal migration disorder). It is characterized by the presence of clumps of neurons near the brain's ventricles. Most people with this disorder are female, as it can be lethal in males.

Symptoms typically begin with seizures in the teenage years. Intelligence is usually normal, but mild intellectual disability (including difficulty with reading and spelling) may occur. People with this condition also appear to be at increased risk for stroke and other vascular or coagulation (clotting) problems. Some people also have hyperflexible joints and vascular anomalies, which also occur in Ehlers-Danlos syndrome (EDS).

X-linked periventricular heterotopia is caused by mutations in the FLNA gene and is inherited in an X-linked dominant manner. Treatment depends on the symptoms in each person and typically includes anti-seizure medications.

EDS with periventricular heterotopia, previously considered a variant of EDS, is now considered to be the same as X-linked periventricular heterotopia type 1 (PVNH1) and is not included as an EDS subtype under the 2017 classification of EDS.

Last updated on 05-01-20

Where can I access articles and case studies related to X-linked periventricular heterotopia?

You can find relevant articles on X-linked periventricular heterotopia through PubMed, a searchable database of biomedical journal articles. Although not all of the articles are available for free online, most articles listed in PubMed have a summary available. To obtain the full article, contact a medical/university library or your local library for interlibrary loan. You can also order articles online through the publisher’s Web site. Using "X-linked periventricular heterotopia" as your search term should help you locate articles. Use the advanced search feature to narrow your search results. Click here to view a search.
http://www.ncbi.nlm.nih.gov/PubMed

The National Library of Medicine (NLM) can help you find libraries in your area where you can get the full text of medical articles. The webpage also describes how you can get these articles through interlibrary loan and Loansome Doc (an NLM document-ordering service). You can search for libraries at the following link http://nnlm.gov/members/.

You can also contact the NLM toll-free at 1-888-346-3656.

Last updated on 05-01-20

How might X-linked periventricular heterotopia be treated?

Although there is no cure for X-linked periventricular heterotopia, there may be ways to manage the signs and symptoms in each individual. Seizures are typically treated with antiepileptic medications. Given the risk for aortic or carotid dissection (leaking of blood into the artery wall), individuals with this condition may be advised to keep blood pressure within the normal range.

Additionally, it is recommended that individuals with X-linked periventricular heterotopia undergo carotid and abdominal ultrasound surveillance studies for aortic and carotid dissection and echocardiograms to monitor valvular abnormalities.

Last updated on 05-01-20

Clinical Research Resources

Christopher A. Walsh Laboratory

The Christopher A. Walsh Laboratory is interested in the development of the cerebral cortex. Abnormal development of the cerebral cortex in humans results in epilepsy, autism, intellectual disability, dyslexia, and other learning disorders, and perhaps some psychiatric conditions as well. Several of their projects are directed at trying to understand the basic biology of the cortex by studying the mutations that disturb its development. Conditions that they are currently researching include: double cortex syndrome, periventricular heterotopia, schizencephaly, perisylvian polymicrogyria and Walker Warburg syndrome. Click on the link above to access further information about this research.

Last updated on 04-27-20

Selected Full-Text Journal Articles

Free full text-X-linked periventricular heterotopia

Lange M, Kasper B, Bohring A, et al. 47 patients with FLNA associated periventricular nodular heterotopia. Orphanet Journal of Rare Diseases. 2015;10:134.

Last updated on 04-27-20

Name: Epilepsy Foundation 8301 Professional Place East Suite 230
Landover, MD, 20785, United States
Phone: +1-301-459-3700 Toll Free: 800-332-1000 (24/7 Helpline) Fax : +1-301-577-2684 Email: contactus@efa.org Url: https://www.epilepsy.com/ en Español 1-866-748-8008
Name: PVNH Support & Awareness 206-1082 West 8th Avenue
Vancouver British Columbia, V6H 1C4, Canada
Phone: +1-604-714-1222 Email: info@pvnhsupport.com Url: http://pvnhsupport.com/

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