RESUMO
Diamond-Blackfan anemia (DBA) is a congenital red cell aplasia arising from ribosomal protein (RP) defects. Affected patients present with neonatal anemia, occasional dysmorphism, and cancer predisposition. An anemic newborn was diagnosed with DBA due to RPL5 mutation (c.473_474del, p.K158SfsX26). Refractory anemia required regular transfusions and iron chelation therapy. Pancytopenia occurred at age 16 years. Bone-marrow studies showed myelodysplasia, erythroblastosis, and clonal evolution of del(20)(q11.2q13.3). Severe anemia required transfusions. Del(20q), including the L3MBTL1 gene, is reported to be relevant to the hematological phenotype of Shwachman-Diamond syndrome. A combined defect of RPL5 and L3MBTL1 may contribute to the aberrant erythropoiesis in the present case.
Assuntos
Anemia de Diamond-Blackfan/sangue , Anemia de Diamond-Blackfan/complicações , Deleção Cromossômica , Cromossomos Humanos Par 20/genética , Evolução Clonal/genética , Eritroblastose Fetal/sangue , Eritroblastose Fetal/etiologia , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/etiologia , Síndromes Mielodisplásicas/genética , Adolescente , Anemia de Diamond-Blackfan/terapia , Transfusão de Sangue , Proteínas Cromossômicas não Histona/genética , Progressão da Doença , Eritroblastose Fetal/genética , Eritropoese/genética , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Síndromes Mielodisplásicas/terapia , Pancitopenia/etiologia , Proteínas Repressoras , Proteínas Ribossômicas/genética , Índice de Gravidade de Doença , Proteínas Supressoras de TumorRESUMO
Some introduced clonal plants spread mainly by vegetative (clonal) propagules due to the absence of sexual reproduction in the introduced range. Propagule pressure (i.e. total number of propagules) may affect the establishment and thus invasion success of introduced clonal plants, and such effects may also depend on habitat conditions. A greenhouse experiment with an introduced plant, Hydrocotyle vulgaris was conducted to investigate the role of propagule pressure on its invasion process. High (five ramets) or low (one ramet) propagule pressure was established either in bare soil or in an experimental plant community consisting of four grassland species. H. vulgaris produced more total biomass under high than under low propagule pressure in both habitat conditions. Interestingly, the size of the H. vulgaris individuals was smaller under high than under low propagule pressure in bare soil, whereas it did not differ between the two propagule pressure treatments in the grassland community. The results indicated that high propagule pressure can ensure the successful invasion in either the grass community or bare soil, and the shift in the intraspecific interaction of H. vulgaris from competition in the bare soil to facilitation in the grassland community may be a potential mechanism.