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International Birth Defects Information Systems
Ataxia - Telangiectasia

International Birth Defects Information Systems




Ataxia - Telangiectasia


Topics: | A-T | Ataxia - Telangiectasia | Idiopathic double athetosis | Louis - Bar Syndrome |

Related Topics: | Disabilities | Birth Defects | Fetal Alcohol Syndrome |

Service Related : | Support Groups | Professional Associations | Key Information Sources |

Languages: | English | Spanish | Ukranian |

Notes per Visitors  
... disorder ... due to a genetic mutation of chromosome 11 ... carriers might be at an increased risk of certain types of cancer ... very sensitive to radiation ...

Ataxia - Telangiectasia
Victor A. McKusick, OMIM, Johns Hopkins University, August 22, 2007
Visitor Comments [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
Visitor Comments"... very brief but it gives a basic understanding of A-T ..."

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

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

National Ataxia Foundation [USA]
Visitor Comments [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: (síndrome de Louis-Bar)
Dres. Marcos Delfino et al., Arch Pediatr Urug 2006; 77(2): 154-158
Visitor Comments [Spanish]
La ataxia-telangiectasia es un síndrome que fue descrito por primera vez en 1926 por Syllaba y Henner (1). Sin embargo, fue la publicación de la neuróloga Denise Louis- Bar en 1941 (2) la que tuvo mayor repercusión en el medio médico y generó la sociación del síndrome a su nombre. La denominación ataxia-telangiectasia llegó por fin con la detallada descripción por parte de Boder y Sedgwick en 1959 (3). Desde entonces otros autores, e incluso múltiples talleres internacionales, han investigado este síndrome, cuyo interés ha aumentado en la medida de conocerse su sustrato molecular. En Uruguay, existen las ublicaciones de la doctora Rebollo en 1961(4) y del doctor Julio Marcos y colaboradores 1962 (5). Se trata de una enfermedad poco recuente (1 caso cada 40 a 100 mil nacimientos) de herencia autosómica recesiva que se transmite a través del cromosoma 11, siendo los portadores (heterocigotos) aparentemente sanos. Un 1 a 2% de la población es portadora (6,7). Clínicamente se manifiesta por ataxia cerebelosa progresiva, distonía, telangiectasias oculocutáneas, retraso en el crecimiento, envejecimiento prematuro, infecciones sinopulmonares recidivantes, riesgo aumentado de cáncer (en particular linfoide) e hipersensibilidad a las radiaciones ionizantes. Otras manifestaciones clínicas pueden ser hipogonadismo y retraso del advenimiento de la pubertad, y diabetes sacarina no cetósica y resistente a la insulina. En 1988 Gatti y colaboradores (8) identificaron la región cromosómica 11q22-23 como la implicada en este síndrome. En 1995 el grupo de Silo (9) identificó en esa región el gen mutado de la ataxia-telangiectasia (ATM). El producto de ese gen resultó ser una proteinquinasa con funciones de “señal” que interviene en el control del ciclo celular, la recombinación de ADN, la apoptosis y otras respuestas celulares al daño de ADN. Las anormalidades en este control mediado por ATM producen ADN dañado, con lo cual se acumulan las roturas cromosómicas con el paso del iempo y la célula muere. Estos fenómenos afectarían especialmente los timocitos, los linfocitos B inmaduros, las células de urkinje del sistema nervioso central y el endotelio vascular (10). La marcha atáxica puede estar presente en el segundo año de vida; a los cuatro años de vida la presentará el 85% de los afectados. La ataxia afecta progresivamente la musculatura axial, de las extremidades, del paladar surgiendo así disartria, babeo, apraxia ocular, coreoatetosis. A los 10 años de vida la marcha independiente es imposible. ...

Ataxia-telangiectasia
Medline Plus, July 1, 2007
Visitor Comments [Spanish]
Nombres alternativos: Síndrome de Louis-Bar ... Definición: Es una enfermedad poco común de la infancia que afecta el cerebro y otras partes del cuerpo. Ataxia se refiere a movimientos descoordinados, como caminar, y telangiectasia es el agrandamiento de los vasos sanguíneos (capilares) justo por debajo de la superficie de la piel. Las telangiectasias aparecen como pequeñas venas rojas similares a una araña.

Ataxia - Telangiectasia
I.B.I.S. Birth Defects, May 8, 2003
Visitor Comments [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: 2008/3/10

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American Medical Association