Ataxia - Telangiectasia
Richard A. Gatti , M.D, GeneReviews, February 15, 2005
[for Professionals mainly]
A-T is characterized by progressive cerebellar ataxia beginning between 1 and 3 years of age, choreoathetosis, telangiectasias of the conjunctivae, and increased sensitivity to ionizing radiation followed by immunodeficiency and malignancy, particularly leukemia and lymphoma, in many patients … Analysis of the ATM gene on chromosome 11q22-q23 is available clinically to aid in the diagnosis of symptomatic patients from certain ethnic groups … Known to have a high prevalence of specific ATM mutations … A-T is suspected in young children who have signs of progressive cerebellar dysfunction … slurred speech … oculomotor apraxia … Serum AFP … Elevated above 10 ng/ml in about 90% to 95% of patients … Most patients with A-T in the United States live beyond 20 years of age … The most common misdiagnosis is cerebral palsy … Radiosensitivity is also seen in Nijmegen Breakage syndrome … Carrier testing may be available to relatives of an affected family member either through direct DNA analysis or through linkage analysis … Epidemiological studies suggest that A-T carriers are at an increased risk for cancer, especially breast cancer … Prenatal testing is clinically available and can utilize DNA mutation analysis.

Ataxia - Telangiectasia
John Hopkins University, 2007
[for Professionals mainly]
Gene Map Locus: 11q22.3 … AT is an autosomal recessive disorder characterized by cerebellar ataxia, telangiectases, immune defects, and a predisposition to malignancy. Chromosomal breakage is a feature. AT cells are abnormally sensitive to killing by ionizing radiation (IR), and abnormally resistant to inhibition of DNA synthesis by ionizing radiation … 4 complementation groups for the classical form of the disease … Clinical Features … Homozygotes … Patients present in early childhood with progressive cerebellar ataxia and later develop conjunctival telangiectases, other progressive neurologic degeneration, sinopulmonary infection, and malignancies. Telangiectases typically develop between 3 and 5 years of age … Ataxia can be misdiagnosed as ataxic cerebral palsy before the appearance of oculocutaneous telangiectases … Gonadal dysfunction in ataxia - telangiectasis was discussed by Miller and Chatten (1967) … The oldest known AT patient … at age 52 years … AT may be the most common syndromic progressive cerebellar ataxia of early childhood. Truncal ataxia precedes appendicular ataxia ... Chromosomal breakage in AT … Leukemia and chromosomal abnormalities occur in at least 2 other mendelian disorders--Fanconi pancytopenia and Bloom syndrome … Lymphomas in AT patients tend to be of B-cell origin … leukemias tend to be of T-CLL type … Other solid tumors, including medulloblastomas and gliomas, occur with increased frequency in AT … Swift et al (1987) examined the cancer risk of heterozygotes for AT in 128 families, including 4 of Amish ancestry, 110 white non-Amish families, and 14 black families. They measured documented cancer incidence rather than cancer mortality … Incidence rates in AT relatives were significantly elevated over those in spouse controls … Breast cancer in women was the cancer most clearly associated with heterozygosity for AT … Estimated that 8 to 18% of patients with breast cancer in the U.S. white population would be heterozygous for AT … Pippard et al (1988) confirmed this observation … Excess of breast cancer deaths in British mothers of AT patients … Most frequent cancer site in the blood relatives was the female breast … Estimated risk of cancer of all types among heterozygotes as compared with noncarriers was 3.8 in men and 3.5 in women … Genes responsible for most cases of AT are located on 11q … Athma et al (1996) determined the AT gene carrier status blood relatives … 33 women with breast cancer who could be genotyped; 25 of these were AT heterozygotes, compared to an expected 14.9 … Athma et al (1996) estimated that, of all breast cancers in the U.S., 6.6% may occur in women who are AT heterozygotes.

NINDS Ataxia Telangiectasia Information Page
National Institute of Neurological Disorders and Stroke, June 1, 2007
"... very brief but it gives a basic understanding of A-T ..."

Ataxia Telangiectasia: Fact Sheet
National Cancer Institute, January 26, 2006
"... very concise overview of A-T ... helpful for families ..."

Ataxia-Telangiectasia Society
"... resource for families ..."

Ataxia - Telangiectasia Mutation Database
Patrick Concannon, May 18, 2007
[for Professionals mainly]

National Ataxia Foundation [USA]
[Support Group]
Established in 1957 … An estimated 150,000 people in the United States are affected.

Questions and Answers: Ataxia Telangiectasia
National Institutes of Health
Ataxia telangiectasia (A-T) is a rare, recessive genetic disorder of childhood that occurs in about 1/40,000 and 1/100,000 persons worldwide. The ailment is progressive.

A-T Children's Project
Created to provide physicians, research scientists, families and support providers with information … What is A-T?

Ataxia - Telangiectasia
I.B.I.S. Birth Defects, May 8, 2003
[Ukrainian]
A fact sheet for parents in Ukrainian
What is ataxia - telangiectasia ... Symptoms and features of the disease ... Prevalence ... Prognosis ... Connection to other diseases ... Inheritance ... Diagnosis ...

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Last Updated: 2007/08/30

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