ATYPICAL HEREDITARY NEUROPATHY WITH LIABILITY TO PRESSURE PALSIES (HNPP) - THE VALUE OF DIRECT DNA DIAGNOSIS

We report two patients with suspected hereditary liability to pressure palsies. Neurophysiological studies showed a mixed axonal-demyelinati ng sensory-motor polyneuropathy with focal slowing of conduction veloc ities at the common sites of entrapment. Morphological studies on sura l nerve biopsy from the proband showed active axonal regeneration with out typical tomacula. Molecular analysis confirmed the presence of a d eletion of chromosome 17p11.2 in both patients. Our observation confir ms the heterogeneity of hereditary liability to pressure palsies and t he relevance of DNA testing for the diagnosis of this hereditary neuro pathy.