Louis-Bar syndrome

a·tax·i·a tel·an·gi·ec·ta·si·a

, ataxia-telangiectasia [MIM*208900]
an autosomal recessive multisystem disorder consisting of ataxia, ocular apraxia, hypotonia, proprioceptive sensory loss, areflexia, and choreoathetosis; onset typically in early childhood; systemic features include increased susceptibility to malignancies, conjunctival and cutaneous telangiectasia, and recurrent pulmonary infections due to immunodeficiencies. Caused by breaks on chromosome 11q at q22-q23, producing failure of DNA repair.
Farlex Partner Medical Dictionary © Farlex 2012


An autosomal recessive condition (OMIM:208900) characterised by sinopulmonary infections, choreoathetosis (wobbly gait), slurring of speech, muscular atrophy and “red eyes”.
Clinical findings
Progressive cerebellar ataxia, oculocutaneous telangiectasia, thymic aplasia or hypoplasia (cellular defect), immune deficiency, autoimmune phenomena.

Decreased IgG4 and IgA2, ± decreased IgE, increased AFP.

Increased susceptibility to radiation-induced chromosomal damage (breakage and rearrangement due to defective DNA repair); increase in lymphoid, breast and other cancers.

Immune complex (IC) deposits in glomeruli, choroid plexus, heart valves and synovium; increase in vasoactive amines (histamine), serotonin, IgE and platelets; presence of macrophages; antigen and antibody valences; class of antibody; antibody:antigen ratio; affinity of antibody:antigen; types of vasculature involved depend on the tissue through which the ICs pass and response of the reticuloendothelial system to the ICs.

Clinical findings, cell culture for radiosensitivity and atypical radioresistant DNA synthesis; cell culture for prenatal diagnosis of ATM mutation.

Symptomatic, supportive; aggressive treatment of infections and surveillance for malignancy.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


Denise, mid-20th century Belgian neuropathologist.
Louis-Bar syndrome - an autosomal recessive disorder characterized by cerebellar ataxia and telangiectasia. Synonym(s): ataxia telangiectasia
Medical Eponyms © Farlex 2012
References in periodicals archive ?
(2) The disorder was further elaborated and delineated as a distinct clinico-pathological entity by Biemond (1957) and Boder and Sedgwick (1957); these latter authors suggested the name Ataxia-telangiectasia and Centerwall and Meller (1958) proposed the eponym Louis-Bar Syndrome.
- Ataxia-Telangiectasia (Louis-Bar Syndrome) Global Clinical Trials Review, H1, 2014
Ataxia-telangiectasia (AT), also known as Louis-Bar syndrome, is a hereditary autosomal recessive progressive multisystem disease.