HMSNL IN A 13-YEAR-OLD BULGARIAN GIRL

We present a 13-year-old Bulgarian girl with a new form of demyelinati ng neuropathy with hearing loss. The clinical and neuropathological fe atures of the patient were similar to those of the recently described hereditary motor and sensory neuropathy type Lom (HMSNL), first identi fied in a large Bulgarian Gypsy population. Neuropathological examinat ion of a peripheral nerve biopsy revealed an excess of nerve fibers wi th inappropriately thin myelin sheaths compared with the axon diameter , surrounded by concentric Schwann cells without typical onion-bulb fo rmation. The parents of our patient are unaware of Gypsy ancestry and are not in a consanguineous marriage. Genetic analyses showed that the patient was homozygous for the predominant HMSNL haplotype on 8q24. O ur findings indicate that HMSNL should be considered in the differenti al diagnosis of any patient presenting with the symptoms of demyelinat ing neuropathy with hearing loss, even if no Gypsy ethnic background i s reported. (C) 1998 Elsevier Science B.V.