Pediatric leukemia susceptibility disorders: manifestations and management

The clinical manifestations of inherited susceptibility to leukemia encompass a wide phenotypic range, including patients with certain congenital anomalies or early-onset myelodysplastic syndrome (MDS) and some with no obvious medical problems until they develop leukemia. Leukemia susceptibility syndromes occur as a result of autosomal dominant, autosomal recessive, or X-linked recessive inheritance, or de novo occurrence, of germline pathogenic variants in DNA repair, ribosome biogenesis, telomere biology, hematopoietic transcription factors, tumor suppressors, and other critical cellular processes. Children and adults with cytopenias, MDS, dysmorphic features, notable infectious histories, immunodeficiency, certain dermatologic findings, lymphedema, unusual sensitivity to radiation or chemotherapy, or acute leukemia with a family history of early-onset cancer, pulmonary fibrosis, or alveolar proteinosis should be thoroughly evaluated for a leukemia susceptibility syndrome. Genetic testing and other diagnostic modalities have improved our ability to identify these patients and to counsel them and their family members for subsequent disease risk, cancer surveillance, and therapeutic interventions. Herein, the leukemia susceptibility syndromes are divided into 3 groups: (1) those associated with an underlying inherited bone marrow failure syndrome, (2) disorders in which MDS precedes leukemia development, and (3) those with a risk primarily of leukemia. Although children are the focus of this review, it is important for clinicians to recognize that inherited susceptibility to cancer can present at any age, even in older adults; genetic counseling is essential and prompt referral to experts in each syndrome is strongly recommended.