Lumbosacral agenesis and anteroposterior split cord malformation in a patient with single central maxillary incisor: case report and review of the literature.

We report an infant born with lumbosacral agenesis, a subcutaneous lumbosacral mass, and a solitary median maxillary incisor. Operatively, a lipomyelomeningocele was noted to extend from the dorsal hemicord of a split cord malformation. Genetically, the child was found to have a defect on chromosome 7q. To our knowledge, this is the first case report of a patient with the rare lumbosacral agenesis and solitary median maxillary incisor. Furthermore, to our understanding, this is only the fourth reported case of split cord malformation in which the hemicords are oriented in the sagittal plane and one of only a few cases reported in the medical literature of simultaneous occurrence of lumbosacral agenesis and occult spinal dysraphism, that is, split cord malformation and lipomyelomeningocele. Following a review of the medical literature, and considering that our patient did indeed have dysmorphology of chromosome 7q, we hypothesize that this single defect resulted in both cranial and caudal deformation, as exemplified by our patient. We review the medical literature for related case reports and potentially related chromosomal abnormalities and various teratogenic substances.