Periventricular Nodular Heterotopia and Distal Limb Deficiency: A Recurrent Association

Malformations of cerebral cortical development, in particular periventricular nodular heterotopia (PNH), and distal transverse limb deficiency have been reported as associated congenital anomalies. Patients with PNH and transverse limb deficiency can be classified as having amniotic band sequence or Adams-Oliver syndrome (AOS). Controversy exists whether these should be considered separate entities. In some AOS patients, autosomal recessive inheritance has been shown, but in most patients causes are unknown, and both environmental and genetic factors have been implicated. We present three patients with PNH and distal transverse limb deficiency to support the hypothesis that these should be considered part of one group of disorders, and highlight the variable severity of the clinical and neuroradiological phenotype. Chromosome abnormalities were excluded by copy number analysis on 250K SNP microarray data.Research done on limb deficiency as on PNH caused by mutations in known genes, suggests the involvement of vascular developmental pathways. The combination of limb deficiency and PNH may have a common causative mechanism. Recognition and grouping of patients with this combination of abnormalities will help elucidating the cause. (C) 2010 Wiley-Liss, Inc.