A case series on transient abnormal myelopoiesis in Down syndrome

• Main Authors: Zulkeflee, Nur Aliah, Zulkeflee, Razan Hayati, Mohd Yunus, Nazihah, Mohd Radzi, Muhammad Amiro Rasyeeq, Mat Zin, Nik Mohd Zulfikri, Ramli, Norhidayah, Mohd Nawi, Nurul Alia, Rasudin, Nur Fatin Syahirah, Abdul Halim, Sarah, M Fuad, Fathy Nabila Najla
• Format: Article
• Language: English
• Published: Faculty of Medicine, UKM 2023
• Subjects: RB Pathology
• Online Access: http://irep.iium.edu.my/110877/1/110877_A%20case%20series%20on%20transient%20abnormal%20myelopoiesis.pdf; http://irep.iium.edu.my/110877/; https://www.medicineandhealthukm.com/article/international-virtual-medical-research-symposium

Introduction: Transient Abnormal Myelopoiesis (TAM) is a myeloproliferative disorder that can develop in 10% to 15% of newborns with Down syndrome. It may present with a high count of blast cells and can resemble congenital leukemia. This series discusses two cases of TAM, both of which achieved sustained remission a few months after their diagnosis. Case Report: In the first case, a baby boy with Down syndrome presented with congenital pneumonia at birth, bilateral eye conjunctivitis and an enlarged liver. Blood film showed 34% blast cells, and thrombocytopenia. After a month of stay he was discharged with a normalized blood count and no detectable blast cells in the peripheral blood film. While the second case involved a baby girl with Down syndrome who was treated for congenital pneumonia. Her total white blood cell count was elevated, with 33% blast cells characterized by prominent nucleoli and bluish, blebbing cytoplasm. After a week, her blast cells increased to 80%. Immunophenotyping performed showed 72% of blast cells which displayed heterogenous positivity for CD34, CD33, HLADR, CD61 (in 54% of blast population), CD41a (in 54% of blast population), CD36, CD56, CD123, and CD9 (megakaryocytic phenotype). They were negative for cy MPO, B and T cell markers. She started treatment with low-dose Cytarabine. Discussion: Down syndrome is associated with TAM and and myeloid leukemia associated with Down Syndrome (ML-DS). The detection of exon2/3 GATA1 mutation via sequencing is essential in the diagnosis of both TAM and ML-DS however this testis not readily available at our center. TAM typically resolves within three months. However, close monitoring is essential because multiorgan failure can lead to a mortality rate of up to 20%.