Epidemiology

---

Etiology

---

Pathophysiology

---

ATM gene mutation → defective dsDNA break repair → accumulation of mutations → tumor development and immunodeficiency (combined B and T cell immunodeficiency)

Clinical features

---

• Neurological features
  • Cerebellar involvement
    • Age of onset: 6–18 months
    • Atrophy of the cerebellar vermis and hemispheres
    • Symptoms
      • Truncal swaying
      • Gait ataxia
• Spider angiomas: telangiectasia that mainly involves the conjunctiva and face
• Immunodeficiency (B and T cell deficiency)
  • Manifests with recurrent sinopulmonary infections
  • Commonly associated with IgA deficiency (e.g., mucosal infection, transfusion-related anaphylaxis)
  • ↑ AFP
• Increased risk of malignancy
  • Lymphoma
  • Leukemia

Diagnostics

---

Treatment

---