A Call for an Early Clinical Consideration for Ataxia-Telangiectasia in Infants with Low TREC and Combined Immunodeficiency
Monday, March 7, 2016
South Exhibit Hall H (Convention Center)
Rony Greemberg, MD, Ronit Herzog, MD
Rationale: Newborn screening by low T-cell receptor excision circle (TREC) has led to an early detection of severe combined immunodeficiency (SCID). Our patient illustrates the importance of early consideration of Ataxia-Telangiectasia (AT) in the setting of abnormally low TRECs with a combined immunodeficiency in a newborn.

Methods: The patient was born at full term to non-consanguineous parents, and exhibited abnormally low TREC levels. From 2 months of age he developed multiple respiratory infections and recurrent otitis media. He was treated with intravenous gamma globulin (IVIG), pentamidine, and filgrastim. The patient developed normally till approximately 15 months of age when he exhibited a wide gait. 

Results: Newborn TREC average was 61 (NL>200/μl). Naïve CD45RA+ CD4 count was  normal. Absolute lymphocyte count, CD4T, CD8T and CD19 cells were low with normal NK number and function. IgA and IgM were absent, IgG was normal. T cells proliferative response was normal, without evidence of maternal engraftment or clonal expansion. Immunization did not result in increased titers. Artemis, RAG1, RAG2, adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), DNA ligase 4, TAC1, BTK, 22q11 deletion, telomeres studies were negative. At a 18 month of age AFP was elevated and AT exon deletion was detected. 

Conclusions: The clinical heterogeneity and onset of symptoms of AT patients lead to delay in diagnosis of those patients. An early diagnosis is important for avoidance of exposure to ionizing radiation, and early management of complications. This case illustrates the spectrum of immunodeficiency presentation of infants with AT.