What is the diagnosis for a patient presenting with cerebellar ataxia and oculocutaneous telangiectasias?

The presentation of cerebellar ataxia and oculocutaneous telangiectasias is characteristic of ataxia telangiectasia, which is a rare genetic disorder. Ataxia telangiectasia is caused by mutations in the ATM gene, which plays a critical role in DNA repair and maintenance. The combination of progressive cerebellar ataxia, which affects balance and coordination, and the development of small dilated blood vessels (telangiectasias) on the skin and conjunctiva is a hallmark of this condition.

Patients with ataxia telangiectasia may also present with a weakened immune system, increased sensitivity to ionizing radiation, and a higher risk for certain types of cancers, particularly lymphomas and leukemias. The features of this disorder tend to manifest in early childhood and can be linked to autosomal recessive inheritance.

Identifying this specific combination of symptoms—particularly the association of cerebellar dysfunction with telangiectasias—guides clinicians toward the diagnosis of ataxia telangiectasia over other disorders that might present with similar symptoms but do not share these key features.