Wilson Marques

17p duplicated Charcot-Marie-Tooth 1A: characteristics of a new population.

AbstractThe most frequentntype of Charcot–Marie–Toothn(CMT) neuropathy is that associatednwith the 17p11.2–p12 chromosomenduplication, whose characteristicsnhave been well described innEuropean and North Americannpopulations. In this study, we analyzedna Brazilian population exhibitingnthe mutation, found in 57npatients from 42 families (79%) ofna cohort of 53 families with demyelinatingnCMT. Almost 20% ofnthe duplicated cases were sporadic.nIn 77% of the duplicated familiesnthe mutation event occurred in thenhot spot area of the CMT1A–Repnregion. Forty–five percent of patientsnwere females, 84% were Caucasiansnand 13% of African descent.nDistal limb weakness was thenmost frequent abnormality, appearingnin 84% of patients, althoughnuncommon manifestationsnsuch as severe proximal weakness,nfloppy baby syndrome, diaphragmaticnweakness and severe scoliosisnwere also observed. One patientnwas wheelchair–bound, and threensuffered severe hand weakness.nSensory abnormalities were detectednin 84% of the cases, but 80%nwere unaware of this impairment.nTwelve patients complained of positivensensory manifestations suchnas pain and paresthesias. Progressionnwas reported by 40%. Motornconduction velocities in the uppernlimbs were always less than 35 m/s,nand less than 30.4 m/s in the peronealnnerve. The findings of thisnstudy expand the clinical spectrumnof the disease.

Clinical and genetic analysis of 29Brazilian patients with Huntington’sdisease-like phenotype

Huntingtons disease (HD) is a neurodegenerative disorder characterized by chorea, behavioral disturbances and dementia, caused by a pathological expansion of the CAG trinucleotide in the HTT gene. Several patients have been recognized with the typical HD phenotype without the expected mutation. The objective of this study was to assess the occurrence of diseases such as Huntingtons disease-like 2 (HDL2), spinocerebellar ataxia (SCA) 1, SCA2, SCA3, SCA7, dentatorubral-pallidoluysian atrophy (DRPLA) and chorea-acanthocytosis (ChAc) among 29 Brazilian patients with a HD-like phenotype. In the group analyzed, we found 3 patients with HDL2 and 2 patients with ChAc. The diagnosis was not reached in 79.3% of the patients. HDL2 was the main cause of the HD-like phenotype in the group analyzed, and is attributable to the African ancestry of this population. However, the etiology of the disease remains undetermined in the majority of the HD negative patients with HD-like phenotype.

Dorsal cutaneous branch of the ulnar nerve: a light and electron microscopy histometric study

This study describes the normal morphology and morphometry of the dorsal cutaneous branch of the ulnar nerve (DCBU) in humans. Fourteen nerves of eight donors were prepared by conventional techniques for paraffin and epoxy resin embedding. Semiautomatic morphometric analysis was performed by means of specific computer software. Histograms of the myelinated and unmyelinated fiber population and the G‐ratio distribution of fibers were plotted. Myelinated fiber density per nerve varied from 5,910 to 10,166 fibers/mm2, with an average of 8,170 ± 393 fibers/mm2. The distribution was bimodal with peaks at 4.0 and 9.5 µm. Unmyelinated fiber density per nerve varied from 50,985 to 127,108, with an average of 78,474 ± 6,610 fibers/mm2, with a unimodal distribution displaying a peak at 0.8 µm. This study thus adds information about the fascicles and myelinated and unmyelinated fibers of DCBU nerves in normal people, which may be useful in further studies concerning ulnar nerve neuropathies, mainly leprosy neuropathy.

Ordering multigene testing in polyneuropathy

Technological advances allow the assessments of multiple genes, e.g., via next-generation sequencing, in a relatively cost-effective manner. As the ability to assess up to thousands of genes by ordering one test becomes more available, determining which genes should be tested, and when in the workup, needs to be determined.