KAT6A::EP300 fusion in congenital myeloid sarcoma: Yet another novel molecular marker indicating spontaneous...

Acute myeloid leukemia (AML)/myeloid sarcoma (MS) is risk-stratified based on cytogenetics. Although most congenital AML/MS have a dismal prognosis, certain genetic variants such as t (8, 16) [KAT6A::cAMP response element-binding protein (CREB) - binding protein fusion] and more recently t (8, 22) [KAT6A::EP300 fusion] have shown spontaneous remissions. KAT6A located on chromosome 8p11 encodes KAT6A protein, a histone/lysine acetyltransferase enzyme. Numerous partner genes associated with KAT6A include cAMP response element-binding protein (CREB) - binding protein (16p13), EP300 (22q13), LEUTX (9q13), NCOA2, NCOA3, and ASXL2.

In this article, we describe an otherwise healthy infant who presented with skin nodules on the face and scalp without any systemic or CNS involvement. A biopsy of the cutaneous lesion was consistent with congenital MS.

Through molecular testing, we found that our patient had the KAT6A::EP300 mutation. This is one of the rare recurrent cytogenetic abnormalities that are linked to congenital AML.

Our patient underwent spontaneous remission with watchful waiting.

Our patient has remained in spontaneous remission for 24 months.

Even though the KAT6A::EP300 mutation in adults is a poor prognostic marker, a similar mutation in congenital AML has a higher likelihood of spontaneous remission. Hence, conservative management might be an initial management strategy for clinically stable patients.