9th June 2025

Ataxia telangiectasia

Ataxia telangiectasia is an autosomal recessive condition whereby patients have defective DNA repair genes. Patients often have low levels of immunoglobulins e.g., IgA and IgG. 

Clinical features

The characteristic features of ataxia telangiectasia are: 

Ataxia, which is cerebellar in nature and first apparent in the toddler age group. Children demonstrate difficulties standing still and walking, with patients often requiring use of a wheelchair after the age of ten. 

Telangiectasia within the conjunctivae of the sclera or over the sun-exposed areas of the skin typically appear by the age of five. Other clinical features are seen below. 

• Learning difficulties 
• Chronic lung disease
• Lymphomas and leukaemias (~25%)
• Poor growth
• Infertility due to gonadal atrophy
• Dysphagia – Due to lack of coordination between mouth and pharynx 

Investigations

• Low immunoglobulin levels e.g. IgA and IgG
• Elevated Alpha- fetoprotein levels (~95% of patients)
• Cerebellar atrophy on MRI

Image Source: Wikimedia Commons (1968). Ataxia Telangiectasia, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Photo_Ocular_telangiectasia_in_a_person_with_A-T.jpg (Accessed 16 June 2025).