What causes megalencephaly?
Megalencephaly occurs when your brain produces too many new brain cells or cells that are too large. It can also occur when metabolic byproducts and matter build up in your brain. Genetic factors and genetic disorders can cause megalencephaly.
What does megalencephaly mean?
Megalencephaly, also called macrencephaly, is a condition in which an infant or child has an abnormally large, heavy, and usually malfunctioning brain. By definition, the brain weight is greater than average for the age and gender of the child.
What is Megalencephaly-capillary malformation syndrome?
DESCRIPTION. Megalencephaly-Capillary Malformation Syndrome (M-CAP or M-CM) is a disorder characterized by overgrowth of several tissues in the body. Its primary features are a large brain (megalencephaly) and abnormalities of small blood vessels in the skin called capillaries (capillary malformations).
What causes polymicrogyria?
There are several known causes for polymicrogyria. The most common of which results from the virus cytomegalovirus (CMV). Other causes include various prenatal infections, brain abnormalities, genetic disorders, and more. This condition may also result from brain injury while a baby is still in the womb.
What causes one side of the brain to be smaller than the other?
The basic cause(s) of HME is not well understood. The disorder occurs because the cells of one hemisphere of the brain grow much more rapidly than do the corresponding cells of the other half of the brain (hamartomatous overgrowth of one hemisphere).
Can hemimegalencephaly cause death?
Although there have been a few reports of medical treatment, the main treatment is radical: remove or disconnect the affected side. However, it has a high mortality, and there have been reports of a vegetative state and seizures resuming, this time in the healthy hemisphere.
When is hemimegalencephaly diagnosed?
Ultrasound diagnosis: There is cerebral overgrowth and ventriculomegaly of one hemisphere resulting in shift in the midline in the standard transverse view of the fetal head. The diagnosis is usually made >26 weeks’ gestation. There are always abnormalities of sulcation, including agyria, pachygyria, or polymicrogyria.
How is megalencephaly related to neuron proliferation?
Megalencephaly is thought to be related to a disturbance in the regulation of cell production in the brain. In normal development, neuron proliferation – the process in which nerve cells divide to form new generations of cells – is regulated so that the correct number of cells is produced in the proper place at the appropriate time.
What does it mean when a child has megalencephaly?
Megalencephaly, also called macrencephaly, is a condition in which an infant or child has an abnormally large, heavy, and usually malfunctioning brain. By definition, the brain weight is greater than average for the age and gender of the child.
What causes most cases of megalencephaly capillary malformation?
Most cases of MCAP are caused by variants in the PIK3CA gene. Most of the identified variants are not inherited, but occur in a fraction of cells as the baby develops (I.e., post-zygotic mutations).
Is there a cure or treatment for megalencephaly?
There is no standard treatment for megalencephaly. Treatment will depend upon the disorder with which the megalencephaly is associated and will address individual symptoms and disabilities. What is the prognosis for megalencephaly?