Constitutional Mosaic Pericentromeric Trisomy 8 in a Female Patient With Aplastic Anemia

Aplastic anemia, characterized by pancytopenia and hypoplastic bone marrow, is associated with various acquired cytogenetic abnormalities, including trisomy 8, in 4%-15% of patients. Constitutional mosaic trisomy 8 notably increases the risks for cytopenia and myeloid malignancies. Duplications near chromosome 8 centromere are associated with developmental delays, autism, and trisomy 8p11.21q11.21 correlates with hematologic disorders. We report a 19-year-old female with constitutional mosaic pericentromeric trisomy 8 presenting with menorrhagia, vitamin B12 deficiency, familial short stature, pancytopenia, and bone marrow aplasia. G-banded chromosome and FISH analyses of her bone marrow and blood samples revealed constitutional mosaic pericentromeric trisomy 8. Chromosomal microarray analysis confirmed mosaic duplications in the 8p12q11.21 region spanning 51 OMIM genes, with 16 identified as OMIM morbid genes, and including 9 genes with autosomal dominant inheritance patterns. FGFR1, ASH2L, ANK1, KAT6A, IKBKB, PLAT, and CEBPD are implicated in hematologic disorders, with FGFR1, ASH2L, KAT6A, and IKBKB showing notable triplosensitivity scores. These regions overlap with 13 published cases (12 papers), of which three displayed hematologic disorders, including neutropenia and juvenile myelomonocytic leukemia. Our case underscores the 8p12q11.21 region as a potential causal region for aplastic anemia, emphasizing the need for further investigation of this patient for possible progression to hematologic malignancy.