Contactin-Associated Protein 1 (CNTNAP1) Mutations Induce Characteristic Lesions of the Paranodal Region

We present the results of nerve biopsy studies of three patients from two unrelated, non-consanguineous families with compound heterozygous CNTNAP1 mutations. The lesions were identical, characterized by a hypomyelinating process; on electron microscopy, we detected, in all nodes of Ranvier, subtle lesions that have never been previously described in human nerves. Transverse bands of the myelin loops were absent, with a loss of attachment between myelin and the axolemma; elongated Schwann cell processes sometimes dissociated the Schwann cell and axon membranes that bound the space between them. These lesions were observed in the area where caspr-1 is located and are reminiscent of the lesions reported in sciatic nerves of caspr-1 null mice. CNTNAP1 mutations appear to induce characteristic ultrastructural lesions of the paranodal region.

Source: Journal of Neuropathology and Experimental Neurology - December 7, 2016 Category: Neurology Authors: Vallat, J.-M., Nizon, M., Magee, A., Isidor, B., Magy, L., Pereon, Y., Richard, L., Ouvrier, R., Cogne, B., Devaux, J., Zuchner, S., Mathis, S. Tags: Original Articles Source Type: research