Neonatal pancytopenia associated with de novo 1q43-44 deletion and 10p15 duplication.

Deletion of 1q43-44 has been reported in >50 cases. Phenotype-genotype correlation of this deletion has recently been described based on 20 pure cases. This led to the definition of critical regions and candidate genes for microcephaly, corpus callosum abnormalities, and seizure disorders. Variable penetrance and expressivity are associated with 1q43-44 microdeletion syndrome, explaining the lack of correlation in rare cases. Despite variation in size of the deletion, most cases are characterized by typical dysmorphic features, but none have demonstrated neonatal pancytopenia. We report on a newborn with partial monosomy 1q43-44 and partial trisomy 10p15.1→10pter born with dysmorphic features and neonatal pancytopenia. Array-CGH analysis characterizes the deletion and the duplication as terminal with estimated sizes of 8 to 9 and 5 to 6 Mb, respectively. Conventional cytogenetic analysis showed the 10p duplication as unbalanced and translocated onto 1q. The deletion in the 1q43-44 region is the largest among the 20 cases reported most recently. The 10p partnership with the derivative 1q43-44 region is unique. We discuss the association of neonatal pancytopenia with 1q deletion and 10p duplication, in light of a recent published case of acute lymphoblastic leukemia in a constitutional case of 1q deletion and 1p duplication.