[Clinical and laboratory analysis of a neonate with Down syndrome and a novel GATA1 gene mutation].

ABSTRACT

OBJECTIVE: To analyze the clinical and molecular biological characteristics of a neonate with myeloid proliferation related to Down syndrome (DS). METHODS: The neonate, who was suspected for Down syndrome, was analyzed in terms of clinical feature, peripheral blood cell morphology, fluorescence in situ hybridization (FISH), immunological classification and other laboratory tests. On hundred and fourteen leukemia-related genes were subjected to next-generation sequencing (NGS). RESULTS: Laboratory test revealed obvious abnormal liver function and coagulation function, anemia, and extreme leukocytosis. Cell smear indicated significantly increased progenitor cells, which conformed to proliferation of megakaryocytes. FISH showed trisomy 21. By NGS, c.220+dupT, a novel mutation, was identified in exon 2 of the GATA1 gene, which encodes a N-terminal activation domain and has a frequency of 95.8%. No mutation was identified among the remaining 113 genes. CONCLUSION: The neonate had DS and GATA1 gene mutation. High percentage of circulating blasts should be considered as transient myelodysplasia but not congenital leukemia.