DNA ANALYSIS AS A TOOL TO CONFIRM THE DIAGNOSIS OF ASYMPTOMATIC HEREDITARY NEUROPATHY WITH LIABILITY TO PRESSURE PALSIES (HNPP) WITH FURTHER EVIDENCE FOR THE OCCURRENCE OF DE-NOVO MUTATIONS

We performed DNA analysis in four families with hereditary neuropathy with liability to pres sure palsy (HNPP). An interstitial deletion of the 17 p 11.2 region was found in typically affected patients as well as in as yet asymptomatic patients. The opportunity for an individual genotyping permitted to ascertain a de novo deletion in one clinically affected case with no relevant familial history. DNA analysis thus be comes the most sensitive tool in diagnosing HNPP, since potentially af fected patients may lack either informative familial history, or clini cal symptoms or even suggestive EMG or histopathological data (tomacul as).