title: Autoimmune lymphoproliferative syndrome in a patient with a new minimal deletion in the death domain of the FAS gene.
abstract: We present a case of autoimmune lymphoproliferative syndrome (ALPS) caused by a previously undescribed minimal deletion in the death domain of the FAS gene. ALPS is an uncommon disease associated with an impaired Fas-mediated apoptosis. The patient presented with a history of splenomegaly since 4 months of age, associated with cervical lymphadenopathy, which improved with oral corticosteroid treatment. Relevant laboratory findings were the presence of anemia, thrombocytopenia, and positive direct and indirect Coombs tests. He was not an offspring of consanguineous parents. Two cervical lymph node biopsies were performed, at 4 years and at 6 years of age. In both lymph nodes, there was marked paracortical expansion by lymphocytes in variable stages of immunoblastic transformation and a very high cell proliferating index. Some clear cells were also present, raising the suspicion of malignant lymphoma. In one of the lymph nodes, there was also a focus rich in large histiocytes with round nuclei and emperipolesis, consistent with focal Rosai-Dorfman disease. Immunostaining showed numerous CD3+ cells, many of which were double-negative (CD4- CD8-) and expressed CD57, especially around the follicles. Molecular studies of the lymph node biopsy showed a point deletion (4-base pair deletion) in exon 9 of the FAS gene (930del TGCT), which results in 3 missense amino acids.
authors: Consultoria em Patologia, Rua Major Leonidas Cardoso 739, PO Box 151, CEP 18602-010, Botucatu, Sao Paulo, Brazil. ggualco@consultoriapatologia.com.br
authors: Gabriela
authors: G
authors: Gualco
authors: Anke
authors: A
authors: van den Berg
authors: Sicco
authors: S
authors: Koopmans
authors: Lívia M
authors: LM
authors: Bacchi
authors: Siderley S
authors: SS
authors: Carneiro
authors: Everaldo
authors: E
authors: Ruiz
authors: Ana Paula
authors: AP
authors: Vecchi
authors: John K C
authors: JK
authors: Chan
mesh_terms: D001327:Autoimmune Diseases / Q000235:genetics*; D002648:Child; D053200:Fas-Associated Death Domain Protein / Q000235:genetics*; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000235:genetics*; D008297:Male; D017384:Sequence Deletion; D019014:fas Receptor / Q000378:metabolism
chemical_list: D053200:Fas-Associated Death Domain Protein; D019014:fas Receptor