What is TUBA1A mutation?
Approximately 40 mutations in the TUBA1A gene have been found to cause isolated lissencephaly sequence (ILS). This condition is characterized by abnormal brain development that results in the brain having a smooth appearance (lissencephaly) instead of its normal folds and grooves.
What causes TUBA1A?
26.4 Mutations in Tubulin Subunits TUBA1A, TUBB2B, and TUBA8 Most cases of type 1 lissencephaly are caused by mutation in either of two microtubule associated proteins LIS1 or DCX.
Is lissencephaly hereditary?
Lissencephaly may be due to various non-genetic and genetic factors. Such factors may include intrauterine infection, insufficient supply of oxygenated blood to the brain (ischemia) during fetal development, and/or different gene mutations. Several gene mutations have been implicated in isolated lissencephaly.
What is microcephaly lissencephaly syndrome?
Lissencephaly, which literally means “smooth brain,” is a rare, gene-linked brain malformation characterized by the absence of normal convolutions (folds) in the cerebral cortex and an abnormally small head (microcephaly). In the usual condition of lissencephaly, children usually have a normal sized head at birth.
What is the 12th chromosome?
Chromosome 12 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 12 spans about 133 million base pairs (the building material of DNA) and represents between 4 and 4.5 percent of the total DNA in cells. Chromosome 12 contains the Homeobox C gene cluster.
What does alpha tubulin do?
Abstract. α- and β-tubulins polymerize to form polarized filaments called microtubules, which are critical for a variety of cellular activities, such as cell division, morphology, and intracellular transport.
Can lissencephaly be diagnosed before birth?
Since there is a wide spectrum of cerebral involvement in lissencephaly, only severe forms of lissencephaly can be detected on prenatal ultrasound; milder degrees of cerebral involvement such as pachygyria and subcortical band heterotopia are difficult to diagnose.
Why is chromosome 12 important?
Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies. Chromosome 12 likely contains 1,100 to 1,200 genes that provide instructions for making proteins. These proteins perform a variety of different roles in the body.
What is alpha beta tubulin?
The alpha beta tubulin heterodimer is the structural subunit of microtubules, which are cytoskeletal elements that are essential for intracellular transport and cell division in all eukaryotes.
What are the symptoms of lissencephaly in children?
Lissencephaly is a disorder of neuronal migration resulting in abnormal cerebral cortical sulcation and gyration. Affected children present with microcephaly, developmental delay, and early-onset epileptic seizures.
When does lissencephaly occur on the anatomic spectrum?
Lissencephaly and pachygyria occur along an anatomic spectrum. In the most severe cases, no sulci (agyria) are evident, but in most patients, some gyri and sulci are present. Children affected with lissencephaly present in infancy with global developmental delay and early-onset epileptic infantile spasms.
What kind of brain disorder is lissencephaly?
Lissencephaly is a disorder of neuronal migration resulting in abnormal cerebral cortical sulcation and gyration.