The clinical phenotype of our patients corresponded to that of HMSNL. The onset was in the

first decade of life, with weakness in their lower limb muscles and gait difficulties. The weakness of the upper limbs and hearing problems occurred in the second decade. Nerve conduction velocities were not measurable due to a total denervation of limb muscles and severe axonal loss. Inhibitors,research,lifescience,medical Hearing loss of our patients was caused by an auditory nerve dysfunction in the presence of preserved cochlear outer hear cell function. The patients had an absence of all neural components of the auditory brainstem potentials beginning with wave I. In the three of the four ears, a positive correlation of otoacoustic emission was found as well as evidence Inhibitors,research,lifescience,medical of cochlear microphonic potentials, which are receptor potentials generated by both inner and outer hear cells (1). All of these findings suggested that the hearing loss in these patients was of neural

origin, as cochlear hear cell function was preserved, but auditory nerve response was abnormal. The absence of caloric responsiveness in one patient was most likely the NU7026 result Inhibitors,research,lifescience,medical of a neuropathy of the vestibular portion of the cochleovestibular nerve rather than a receptor disorder. The absence of vestibular disorder symptoms may have been the result of the gradual occurrence of a bilateral vestibular disorder, allowing the development of mechanisms that would compensate for altered vestibular inputs (2). The clinical and electrophysiological Inhibitors,research,lifescience,medical findings in our cases correlated with those already published (3, 4). HMSNL was first described in a Bulgarian Gypsy population near Inhibitors,research,lifescience,medical Lom (5), and later has been found in Gypsy communities in Italy, Spain, Slovenia, and Hungary (6, 7, 2,

8). Lower limb muscle wasting and weakness characterized the phenotype in the first decade of life followed by upper limb weakness and wasting in the second decade and hearing problems in the third decade (3). Electrophysiological studies revealed severely reduced motor nerve conduction velocity in younger patients and unobtainable in older patients. Biopsy findings showed demyelinating disorder and significant loss of large axons. Brainstem auditory many evoked potentials did not contain neural component (2). Eight to ten million Gypsies who live in Europe today are described as a conglomerate of genetically isolated founder populations. To date, a number of rare autosomal recessive disorders caused by “private Gypsy” mutations have been described (9). Autosomal recessive forms of demyelinating Charcot-Marie-Tooth (CMT4) disease among European Gypsies are caused by private founder mutations.