PREVIOUSLY HEALTHY 15-MONTH OLD FEMALE WITH RAPIDLY PROGRESSIVE ATAXIA AND MILESTONE REGRESSION

Abstract

Introduction Primary immunodeficiencies can present with physical findings that may not be readily apparent to members of the healthcare team. Early recognition of PI improves quality of life and reduces comorbidities. Here we describe a challenging case where physical findings led to a rare diagnosis. Case Description Our previously healthy patient was initially evaluated at the age of 15 months for recurrent “dizziness” and poor balance. Between the ages of 15 and 22 months, her neurologic symptoms worsened. Extensive imaging revealed no abnormalities. An ENT evaluation was undertaken secondary to persistent middle ear effusions. Around the age of 22 months a Pediatric Neurologist finally determined that her symptoms represented ataxia and not developmental delay. Evaluation at that point included measurement of alfa fetoprotein levels which were markedly abnormal. After referral to our tertiary academic center, an immunologic evaluation revealed abnormal quantitative immunoglobulins, marked lymphopenia and absent response to polysaccharide antigens when challenged with the pneumococcal polysaccharide vaccine. Genetic testing confirmed the suspected diagnosis of Ataxia Telangiectasia and revealed the presence of two novel mutations in the ATM gene that had not been previously reported. Discussion Ataxia Telangiectasia typically presents in an older child with a history of recurrent infections, ataxia, and telangiectasias of the eyes. Our patient's early onset ataxia was striking, and even trained neurologists struggled with the diagnosis. We propose that the two novel mutations, being premature stop codons, may explain her very early onset ataxia and rapid neurologic decline compared to the natural history of other patients with Ataxia Telangiectasia.