Clinical and molecular epidemiology of neonatal leukemia in Brazil

Abstract

The clinical and molecular findings of 77 cases of neonatal leukemia (NL) and 380 of infant leukemia (IL) were selected to distinguish features between NL and IL. Somatic gene mutations associated with acute leukemia including FLT3, RAS and PTPN11 were revisited. There were 42 cases of congenital leukemia associated with Down syndrome (DS) and 39 of these cases presented features of acute myeloid leukemia (AML)-M7. Twenty-seven of the DS cases underwent spontaneous remission and were reclassified as a transient myeloproliferative disorder. GATA1 mutations were found in 70% of these cases. In non-DS, frequent abnormalities were MLL rearrangements, mainly MLL–AFF1 in acute lymphoblastic leukemia and MLL–MLLT3 in AML. The FLT3 mutation was not found, while RAS (n = 4) and PTPN11 (n = 2) mutations were identified and reported for the first time in NL. There was substantial evidence to support that somatic abnormalities occur in utero. Thus, congenital leukemia is a good model for understanding leukemogenesis.

Keywords::

• Congenital acute lymphoblastic leukemia
• acute myeloid leukemia
• FLT3
• KNRAS
• PTPN11
• MLL
• GATA1

Acknowledgements

This work was made possible due to the collaboration of physicians from different regions of Brazil who provided samples and clinical data. San Francisco Edit personnel polished the English language (http://www.sfedit.net).

Potential conflict of interest

Disclosure forms provided by the authors are available with the full text of this article at www.informahealthcare.com/lal.

Supplementary material available online

Supplementary Table I showing characteristics of neonates.