Bruton tyrosine kinase (Btk), a non-receptor-associated tyrosine kinase of the Tec family, appears to participate in many myeloid cell functions. We show that macrophages from X-linked ...immunodeficient (XID) mice lacking functional Btk cannot generate efficient bursts of reactive oxygen intermediates (ROIs). The induction of apoptotic cell death by inflammatory stimuli is also enhanced in XID macrophages. Phagocytosis of bacterial particles is only marginally affected in them. In vivo, XID mice show reduced severity of inflammatory diseases in models of experimental autoimmune encephalomyelitis (EAE), dextran sulfate sodium (DSS)-induced colitis, and carrageenan-induced acute edema. Also, polymorphonuclear neutrophil granulocytes (PMNs) in XID mice show poor ROI and nitric oxide (NO) induction, along with a reduction in PMN recruitment to peritoneal inflammation. XID mice show reduction in PMN numbers in peripheral blood, and their bone marrow shows a reduction in the numbers of both monocytic and granulocytic lineages, extending to the earliest progenitor populations. Thus, Btk is likely to play a significant role at multiple points during the development and functioning of the myeloid lineages, affecting the outcome of many infectious as well as noninfectious inflammatory events in vivo. (Blood. 2004;104:1191-1197)
The Forkhead box N1 (FOXN1) is a transcriptional factor regulating the development, differentiation and function of thymic epithelial cells; maintaining T-lineage progenitors in bone marrow; ...promoting terminal differentiation of epithelial cells of hair follicles. Mutation in FOXN1 was reported to cause a rare disorder characterized by rudimentary thymus gland, T-cell immunodeficiency, congenital alopecia and nail dystrophy within an Italian community. This is the first report of FOXN1 p.R255X mutation from India, outside this endogamous Italian community. Out of the two affected children, only one was alive during the genetic evaluation and had all the clinical manifestations such as alopecia totalis and nail dystrophy. The proband was homozygous for FOXN1 p.R255X Italian founder mutation. The carrier status of both the parents was established. Immunological study of the proband revealed total absence of T-cells confirming T-cell immunodeficiency. Prenatal diagnosis during third pregnancy revealed absence of FOXN1 mutation. To conclude, this is the first report of FOXN1 mutation from India highlighting that diseases once confined to certain geographical areas are spreading across the globe probably due to human migrations.
•First report of FOXN1 founder Italian mutation reported from India•Baby exhibited classical features of Nude/SCID mice syndrome.•Total absence of T-cells was observed.•Low levels of IgG•Not responsive to hematopoietic stem cell transplant
