Deficiency of ADA2 mimicking autoimmune lymphoproliferative syndrome in the absence of livedo reticularis and vasculitis

Pediatr Blood Cancer. 2018 Apr;65(4). doi: 10.1002/pbc.26912. Epub 2017 Dec 22.

Abstract

Adenosine deaminase-2 (ADA2) deficiency (DADA2) is associated with early onset polyarteritis nodosa and vasculopathy. Classic presentation includes livedo reticularis, vasculitis, and stroke. However, the phenotype and disease severity are variable. We present a 5-year-old female who presented with features that mimicked autoimmune lymphoproliferative syndrome (ALPS) in the absence of classic features of DADA2. Exome sequencing identified a novel homozygous splicing variant in ADA2 c.882-2A > G. Patient responded to anti- tumor necrosis factor medication and is in complete remission. Hematologists should be aware of various hematological presentations of DADA2, including ALPS-like disorder, that might lack vasculitis and livedo reticularis to prevent delay in initiating optimal therapy.

Keywords: ADA2 deficiency; anti-TNF; autoimmune lymphoproliferative syndrome.

MeSH terms

  • Adenosine Deaminase / deficiency*
  • Autoimmune Lymphoproliferative Syndrome* / diagnosis
  • Autoimmune Lymphoproliferative Syndrome* / enzymology
  • Autoimmune Lymphoproliferative Syndrome* / genetics
  • Child, Preschool
  • Exome*
  • Female
  • Humans
  • Intercellular Signaling Peptides and Proteins / deficiency*
  • Livedo Reticularis*
  • Point Mutation*
  • Vasculitis*

Substances

  • Intercellular Signaling Peptides and Proteins
  • ADA2 protein, human
  • Adenosine Deaminase