Congenital Amniotic Band Syndrome and MLL Rearranged Neonatal Leukemia in an Infant with Multiple Pre-Conception and In Utero Exposures.

Introduction: Patients with birth defects have a higher incidence of cancer; however, an association of amniotic band syndrome (vascular disruption syndrome) with congenital leukemia has never been reported. We characterized a case of MLL-rearranged leukemia in a neonate affected with this birth defect.

Methods: The MLL translocation was characterized in peripheral AML blasts by karyotype analysis, multicolor FISH, Southern blot analysis and genomic and cDNA panhandle PCR. NQO1 genotype was determined by real-time PCR.

Clinical history and results: The infant was born at 38 weeks gestation by C-section for suboccipital encephalocele to a 21 year-old gravida 3 para 2 mother with a history of cigarette, marijuana, cocaine and opiate use, and antidepressant, antipsychotic, barbiturate, caffeine and proton pump inhibitor treatment during pregnancy. Drug screen at delivery was positive for opioids and barbiturates. In addition to the encephalocele, a circular constriction of the right arm, consistent with amniotic band syndrome, and blueberry muffin lesions were noted at delivery. The CBC showed mild thrombocytopenia that resolved the next day. Congenital infection was excluded. The encephalocele was repaired. At 19–20 days of age the infant became septic and hepatosplenomegaly and hyperleukocytosis were observed. The peripheral smear and flow cytomery revealed acute myeloid leukemia with monocytic differentiation (CD45+ population positive for CD4, CD14, CD33, CD38, HLA-DR). Karyotype analysis showed a complex structural abnormality disrupting chromosomes 4, 11 and 19 involving MLL. M-FISH showed insertion of chromosome 11 material into a chromosome 19 and translocation between chromosomes 11q and 4q. The infant received cytosine arabinoside and daunomycin but succumbed to AML, sepsis and multi-organ failure within 4 days. Autopsy showed marrow, viscera, brain and skin infiltration with AML and Chiari type III brain malformation. Southern blot analysis detected two MLL bcr rearrangements. Panhandle PCR demonstrated fusion of MLL intron 6 and intron 1 of ELL from band 19p13.1. Short sequence homologies at the breakpoint junction suggested DNA damage resolution by NHEJ repair. The corresponding transcript joined MLL exon 6 to ELL exon 2. The infant was wild-type at NQO1 C609T.

Conclusions: This is the first association of amniotic band syndrome and congenital AML, both of which are rare conditions. Although the cause(s) are unknown, both conditions originate in utero and maternal exposures during pregnancy may be relevant. There was a history of maternal fetal loss, which is a risk factor for leukemia in infants. The NQO1 substrate p-benzoquinone in cigarette smoke is a topoisomerase II poison, but the infant did not harbor the NQO1 variant that predisposes to leukemia. Cocaine is an in utero exposure implicated in amniotic band syndrome. The occurrence of amniotic band syndrome and congenital AML in this infant raises questions about potential host predisposition or gene-environment interactions common to both conditions. Alternatively, both rare conditions may have occurred by chance alone in the setting of the many in utero exposures.