A Novel Nonsense Homozygous Mutation in <I>SMARCD2</I> Gene Causing Specific Granulocyte Deficiency Type 2: Case Report

<i>Background: </i>Specific granulocyte deficiency type 2(SGD2) is a rare disorder of neutrophil defect caused by mutation in <I>SMARCD2</I> gene characterized by neutropenia, recurrent infections, skin and mucosal ulceration. <i>Objective: </i>We aim to describe a symptomatic patient with a novel homozygous nonsense variant in <I>SMARCD2</I> to help expand the phenotypic description of this rare disease. <i>Methods: </i>A retrospective chart review was conducted on our patient. Data collection included information on demographic, clinical and laboratory data. <i>Results: </i>We report a 4 years old boy with history of delayed separation of cord, recurrent sepsis, skin infections as well as mucocutaneous ulceration, gastrointestinal bleeding and Epstein Barr virus induced lymphoproliferation. He had variable neutropenia, bone marrow biopsy revealed hypogranular neutrophils and no blast excess. Whole genome analysis detected a novel homozygous variant in <I>SMARCD2</I> gene c.208C > T p.(Gln70*). <i>Conclusion: </i>This case report aims to provide insight on additional clinical and molecular features of SGD2. It also sheds light on potential role of <I>SMARCD2</I> gene in other immune cells.