Myeloproliferative disorder in Noonan syndrome.

Abstract

Children with Noonan syndrome (NS) are at increased risk of developing juvenile myelomonocytic leukemia (JMML) or a myeloproliferative disorder associated with NS (MPD/NS) resembling JMML in the first weeks of life; whereas JMML is an aggressive disorder requiring hematopoietic stem cell transplantation, MPD/NS may resolve without treatment and cases with spontaneous remission have also been reported. Two cases of NS with hematologic disorders are described. Diagnosis of the syndrome was confirmed by the identification of earlier reported germline missense mutations in the PTPN11 gene. Splenomegaly in 1 patient and leukocytosis, monocytosis and "in vitro" culture assays consistent with JMML in both were the most salient hematologic features. After a 24-month follow-up, these 2 infants continue to improve and JMML has been ruled out. Splenomegaly persists in 1 patient and monocytosis in both, but without signs of malignancy, thereby suggesting abnormal hematopoiesis or MPD/NS, as described in NS.

• Authors: Pilar Bastida, Sixto García-Miñaúr, Begoña Ezquieta, José Luis Dapena, José Sanchez de Toledo
• Journal: Journal of pediatric hematology/oncology (J Pediatr Hematol Oncol) Vol. 33 Issue 1 Pg. e43-5 (Jan 2011) ISSN: 1536-3678 [Electronic] United States
• PMID: 20829714 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• PTPN11 protein, human
• Protein Tyrosine Phosphatase, Non-Receptor Type 11

Topics

• Follow-Up Studies
• Humans
• Infant
• Infant, Newborn
• Leukemia, Myelomonocytic, Juvenile (genetics, therapy)
• Male
• Mutation, Missense
• Myeloproliferative Disorders (complications, diagnosis, genetics, therapy)
• Noonan Syndrome (complications, diagnosis, genetics)
• Protein Tyrosine Phosphatase, Non-Receptor Type 11 (genetics)