Monoclonal Gammopathy of the Immunoglobulin a Class in a Two-Year-Old Girl with Ataxia Telangiectasia

Ataxia telangiectasia is an autosomal recessive neurologic disorder which is frequently associated with a deficiency of IgA immunoglobulin. We report an unusual case of monoclonal gammopathy of the IgA kappa type in a 2-year-old female patient newly diagnosed with ataxia telangiectasia. Quantitative analysis of the patient's immunoglobulins revealed a marked elevation in the IgA fraction with a value of 672 mg/dL (normal 14–123 mg/dL). The IgG and IgM fractions were normal. Serum protein electrophoresis showed a band of restricted mobility present in the gamma region, which was identified as a monoclonal IgA kappa immunoglobulin on immunofixation electrophoresis. This is the first case report of a patient with ataxia telangiectasia associated with an IgA monoclonal gammopathy.