Ataxia Telangiectasia

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Abstract

Ataxia-telangiectasia is an inherited disease related to an autosomal recessive trait. This means that both parents must provide a defective gene for the child to have symptoms of the disorder.
The disease results from defects in the ataxia telangiectasia mutated (ATM) gene. Defects in this gene can lead to abnormal cell death in various places of the body, including the part of the brain that helps coordinate movement. During development boys and girls are equally affected.

Symptoms can include obvious gross decreased coordination of movements in late childhood to include delayed eye hand coordination, uncoordinated or jerky gait which comes from cerebellar ataxia, decreasing mental development, discoloration of skin areas, enlarged blood vessels in the skin of nose, ears, and inside of the elbow and knee, enlarged blood vessels in the sclera, nystagmus as a late sign, seizures and even severe recurring respiratory infections unfortunately there are not treatments as of yet for this illness and we can only treat the symptoms as they occur and progress. Life expectancy and prognosis decreases throughout the years but can vary. The only prevention of this illness that is known today is that parents with this known genetic train to abstain from trying to have children with out genetic counseling first.

“Ataxia telangiectasia, also refereed to as AT or Louis-Bar Syndrome) is a primary rare, neurodegerative, inherited immunodeficiency disease that affects a number of different organs in the body but primarily the CNS. An immunodeficiency disease is one that causes the immune system to break down, making the body susceptible to diseases. A rare, recessive genetic disorder of childhood that occurs in between 1 out of 40,000 and 1 out of 100,000 persons worldwide. The disease is generally fatal to patients by the time they reach their twenties and it effects both boys and girls are the same rate”.

A-T is characterized by neurological problems, particularly abnormalities of balance, recurrent sinus and respiratory infections, and dilated blood vessels in the eyes and on the surface of the skin. t impairs certain areas of the brain including the cerebellum, causing difficulty with movement and coordination. Patients usually have immune system abnormalities and are very sensitive to the effects of radiation treatments.

In the United States, where recurrent infections typical of the disorder are usually controlled by antibiotics, patients are at high risk of developing and dying of cancer, particularly leukemias and lymphomas due to to depressed immune system and the fact that AT can actually prevent the repair of broken DNA, increasing the risks of above listed cancers.

Symptoms most often first appear in early childhood when children begin to walk and though they usually will start walking at a normal age, their ability to perform this function will appear very problematic. In late pre-school and early school age patients will develop issues with extra ocular motor control. Though they will still be able to focus on objects and see clearly, they will have issues purposely turning their eyes towards an object or sound. Patients can develop numerous respiratory infections.

“A-T is caused by a defect in the ATM gene, which is responsible for managing the cell’s response to multiple forms of stress including double-strand breaks in DNA. In simple terms, the protein produced by the ATM gene recognizes that there is a break in DNA, recruits other proteins to fix the break, and stops the cell from making new DNA until the repair is complete”.

If this ATM gene is not present, ion channels in neurons are degraded and chemical activity is retarded, slowed and even stopped thus creating a lapse in communication between axons and other neurons long that communication pathway to organs and other sensory pathways. Purkinje and granule cells are often affected as well and...
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