Snapshot A 3-year-old boy is brought to the clinic by his mother due to a severe ear infection. She is upset because he just recovered from one about two months ago. On exam, he has multiple telangiectasias on his face and walks with difficulty. On further questioning, his mother reveals that though he has learned to walk at 1 year of age he instead has not improved steadily like his older sister, but seems to have regressed. He is clumsy when walking and his trunk seems unstable. Introduction Primary immunodeficiency of B and T cells Pathogenesis mutation in ATM gene, encoding a DNA repair enzyme unable to repair double-stranded breaks in DNA before cell division leads to genomic instability, development of cancers cerebellar degeneration Genetics autosomal recessive To remember: 4A's ATM gene Ataxia (cerebellar defects) spider Angiomas (telangiectasia) IgA deficiency Presentation Symptoms ataxia onset in childhood telangiectasias onset in childhood recurrent sinopulmonary infections ears, sinuses, lungs Physical exam multiple telangiectasias, most commonly on face and ears also on conjunctival sclera (see above photo) ocular movement abnormalities (strabismus, nystagmus) cerebellar ataxia dysmetria dysdiadochokinesia hypotonia Evaluation Serologies ↑ AFP ↓ IgA ↓ IgG and IgE Labs ↓ lymphocytes Imaging MRI will show cerebellar atrophy Differential Cerebral palsy Friedreich ataxia Gaucher disease or Niemann-Pick diease Treatment Rehab for ataxia For recurrent infections IVIG antibiotics Prognosis, Prevention, and Complications Prognosis variable rate of progression death often by early adulthood eventually wheelchair-bound Complications recurrent infections risk of malignancy (lymphoma, leukemias)