Motor-sensory neuropathy without minifascicles in a patient with 46XY gonadal dysgenesis

We report a 36-year-old patient with 46XY pure gonadal dysgenesis (GD), who manifested a syndrome of progressive motor-sensory neuropathy. Sural nerve biopsy showed severe axonal neuropathy. Since reported cases of chronic motor-sensory neuropathy and pure gonadal dysgenesis have been characterized by nerve biopsy evidence of minifascicle formation, we suggest that this clinical association may be a new type of hereditary motor-sensory neuropathy, not necessarily associated with minifascicle formation.

Episodic ataxia and hemiplegia caused by the 8993T->C mitochondrial DNA mutation

The m.8993T-->C MTATP6 mutation of mitochondrial DNA (mtDNA) usually causes mitochondrial disease in childhood, but was recently described in a family with adult onset ataxia and polyneuropathy. Cytochrome c oxidase muscle histochemistry, which is the standard clinical investigation for mitochondrial disease in adults, is usually normal in patients with MTATP6 mutations. This raises the possibility that these cases have been missed in the past. We therefore studied 308 patients with unexplained ataxia and 96 patients with suspected Charcot-Marie-Tooth disease to determine whether the m.8993T-->C MTATP6 mutation is common in unexplained inherited ataxia and/or polyneuropathy. We identified a three-generation family with the m.8993T-->C mutation of mtDNA. One subject had episodic ataxia (EA) and transient hemipareses, broadening the phenotype. However, no further cases were identified in an additional cohort of 191 patients with suspected EA. In conclusion, m.8993T-->C MTATP6 should be considered in patients with unexplained ataxia, CMT or EA, but cases are uncommon.

Hereditary neuropathy with liability to pressure palsies in a Turkish patient (HNPP): a rare cause of entrapment neuropathies in young adults

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant nerve disease usually caused by 1,5 Mb deletion on chromosome 17p11.2.2-p12, the region where the PMP-22 gene is located. The patients with HNPP usually have relapsing and remitting entrapment neuropathies due to compression. We present a 14-year-old male who had acute onset, right-sided ulnar nerve entrapment at the elbow. He had electrophysiological findings of bilateral ulnar nerve entrapments (more severe at the right side) at the elbow and bilateral median nerve entrapment at the wrist. Genetic tests of the patient demonstrated deletions in the 17p11.2 region. The patient underwent decompressive surgery for ulnar nerve entrapment at the elbow and completely recovered two months after the event. Although HNPP is extremely rare, it should be taken into consideration in young adults with entrapment neuropathies.

A novel point mutation in PMP22 gene in an Italian family with hereditary neuropathy with liability to pressure palsies

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant inherited disorder characterized by recurrent sensory or motor dysfunction. In 85% of HNPP cases the genetic defect is a 1.4 Mb deletion on chromosome 17p11.2, encompassing the PMP22 gene. Point mutations in the PMP22 gene responsible for HNPP phenotypes are rare. We investigated a 17-years-old girl who led to our detecting a novel mutation in PMP22 gene. The mutation was also detected in her father and corresponded to a deletion of one tymidine at position 11 in exon2 (c.11delT). This novel mutation creates a shift on the reading frame starting at codon 4 and leads to the introduction of a premature stop at codon 6.

Hereditary neuropathies

PURPOSE OF REVIEW

The purpose of this review is to help neurologists understand new concepts in hereditary neuropathies, from the clinician's point of view, in the molecular era after the burst of information regarding peripheral nerve biology.

RECENT FINDINGS

Recent studies have focused on understanding the pathomechanisms involved in hereditary neuropathies. In the past year identification of new genes has slowed down since scientists have concentrated more on the function of genes causing Charcot-Marie-Tooth disease and Schwann cell-axon interactions to reveal the molecular cell biology of the disease. Animal models for the most common subtypes of human Charcot-Marie-Tooth disease are now available.

SUMMARY

Rapid advances in the molecular genetics and cell biology of hereditary neuropathies have highlighted the great genetic complexity of Charcot-Marie-Tooth disease. The evolution from a simple clinical classification to a complex molecular one has not facilitated our understanding of the disease. Moreover, the new molecular classification is not simple to use as different mutations of the same gene produce a range of phenotypes. The clinicians have to look for specific clinical and electrophysiological clues to direct the patient to appropriate genetic testing.

[Silver syndrome--case report]

Silver syndrome (Silver spastic paraplegia syndrome) is a rare disorder of the peripheral nervous system that combines features of spastic paraparesis and peripheral neuropathy. The underlying genetic defects are two mutations in the BSCL2 gene which have been described in several families. Silver syndrome--related to the N88S mutation in the BSCL2 gene--is characterized by a spectrum of clinical findings. The coexistence of sensory fiber damage and motor deficit leads to the diagnosis of Charcot-Marie-Tooth disease in some patients, while others are diagnosed with spastic paresis due to predominant pyramidal symptoms. If the symptoms are limited to the motor deficit, hereditary motor neuropathy is diagnosed in some cases. In this report, we describe a case of the Silver syndrome in a Polish family that has been verified by genetic testing. Due to the lack of pyramidal symptoms and slightly expressed sensory fiber damage (in neurographic studies), motor neuropathy type of the Silver syndrome with minor sensory component was diagnosed.

Refinement of a locus for autosomal dominant hereditary motor and sensory neuropathy with proximal dominancy (HMSN-P) and genetic heterogeneity

Hereditary motor and sensory neuropathy with proximal dominancy (HMSN-P) is an adult-onset peripheral neurodegenerative disorder which has been reported only in the Okinawa Islands, Japan. The disease locus of "Okinawa-type" HMSN-P has been previously mapped to 3q13.1, with all affected individuals sharing an identical haplotype around the locus, suggesting that the undiscovered causative mutation in HMSN-P originated from a single founder. We have newly found two large families from the western part of Japan within which multiple members developed symptoms similar to those exhibited by HMSN-P patients from Okinawa, with no record of affinal connection between the islands. Using these pedigrees with "Kansai-type" HMSN-P, we carried out a linkage study utilizing eight microsatellite markers and identified a candidate region on 3q13.1 cosegregating with the disease (maximum two-point LOD score of 8.44 at theta=0.0) overlapping with the Okinawa-type HMSN-P locus. However, the disease haplotype shared among all affected members in these families was different from that in the Okinawa kindred, suggesting allelic heterogeneity. Such allelic variation should aid in the identification of the disease-causative gene. Moreover, the allelic heterogeneity of HMSN-P in the Japanese population suggests that HMSN-P may be more common across other ethnic groups, but classified into other disease categories.

[Clinical report of hereditary motor and sensory neuropathy with proximal dominance in Shiga prefecture]

We followed eight hereditary motor and sensory neuropathy patients with proximal dominance (HMSN-P) in Shiga prefecture from 1984 to 2007. There were 4 men and 4 women from two families showing autosomal and dominant prepotency. These families were related by marriage. The average onset of disease was at 53.4 +/- 8.9 (40-68) years-old. Initial symptoms were difficulty of standing up, difficulty elevating their arms, limping, or numbness. The main feature was neurogenic muscular atrophy with proximal dominance. All deep tendon reflexes were decreased or nonexistent. Paresthesia in the hands and feet and/or decreased vibratory sense in the legs were found in six patients. High CK blood levels were recognized in three patients. EMG in four patients revealed neurogenic pattern. Nerve conduction study was conducted in two patients. MCV of the median nerve and of the tibial posterior nerve, also SCV of the median nerve and of the sural nerve were within normal range in all nerves. Amplitudes of sensory action potential or of M wave were decreased or nonexistent in five of eight nerves, and distal latency of M waves was delayed in three of four nerves. These data suggests dysfunction of distal parts of the peripheral nerve fibers and axonal degeneration of the nerve trunk. Seven patients have died, and their average death age was 69.1 +/- 8.2 (52-77) years-old. Their average affected period was 16.6 (4-30) years. Their clinical history resembles Okinawa-type HMSN-P, but without the painful muscle cramps which are distinctive Okinawa-type signs.

Oral curcumin mitigates the clinical and neuropathologic phenotype of the Trembler-J mouse: a potential therapy for inherited neuropathy

Mutations in myelin genes cause inherited peripheral neuropathies that range in severity from adult-onset Charcot-Marie-Tooth disease type 1 to childhood-onset Dejerine-Sottas neuropathy and congenital hypomyelinating neuropathy. Many myelin gene mutants that cause severe disease, such as those in the myelin protein zero gene (MPZ) and the peripheral myelin protein 22 gene (PMP22), appear to make aberrant proteins that accumulate primarily within the endoplasmic reticulum (ER), resulting in Schwann cell death by apoptosis and, subsequently, peripheral neuropathy. We previously showed that curcumin supplementation could abrogate ER retention and aggregation-induced apoptosis associated with neuropathy-causing MPZ mutants. We now show reduced apoptosis after curcumin treatment of cells in tissue culture that express PMP22 mutants. Furthermore, we demonstrate that oral administration of curcumin partially mitigates the severe neuropathy phenotype of the Trembler-J mouse model in a dose-dependent manner. Administration of curcumin significantly decreases the percentage of apoptotic Schwann cells and results in increased number and size of myelinated axons in sciatic nerves, leading to improved motor performance. Our findings indicate that curcumin treatment is sufficient to relieve the toxic effect of mutant aggregation-induced apoptosis and improves the neuropathologic phenotype in an animal model of human neuropathy, suggesting a potential therapeutic role in selected forms of inherited peripheral neuropathies.

Hereditary motor and sensory neuropathy (proximal dominant form, HMSN-P) among Brazilians of Japanese ancestry

Hereditary motor and sensory neuropathy (proximal dominant form, HMSN-P) has been reported exclusively from Okinawa Prefecture in Japan. We herein report three brothers with HMSN-P who are among Brazilians of Japanese ancestry. They showed the typical clinical manifestations and were compatible with HMSN-P. Okinawa Prefecture has been a site of emigration to other countries, mainly in South America, since 1908. Although this is the first reported familial case of HMSN-P occurring outside Japan, it is estimated that there are 19 or 20 individuals with HMSN-P among these emigrants. Since HMSN-P might be misdiagnosed as familial amyotrophic lateral sclerosis or spinal muscular atrophy, neurologists in countries where individuals of Okinawan extraction reside should be aware of this hereditary neuropathy. HMSN-P should no longer be regarded as an endemic condition limited to Okinawa.

Functional, histopathologic and natural history study of neuropathy associated with EGR2 mutations

Mutations in the EGR2 gene cause a spectrum of Charcot-Marie-Tooth disease and related inherited peripheral neuropathies. We ascertained ten consecutive patients with various EGR2 mutations, report a novel de novo mutation, and provide longitudinal clinical data to characterize the natural history of the peripheral neuropathy. We confirmed that respiratory compromise and cranial nerve dysfunction are commonly associated with EGR2 mutations and can be useful in guiding molecular diagnosis. We also contrast morphological studies in the context of the I268N homozygous recessive mutation affecting the NAB repressor binding site and the R359W dominant-negative mutation in the zinc-finger domain.

Further evidence for genetic heterogeneity of distal HMN type V, CMT2 with predominant hand involvement and Silver syndrome

OBJECTIVE

Distal hereditary motor neuropathy type V (dHMN-V) and Charcot-Marie-Tooth syndrome (CMT) type 2 presenting with predominant hand involvement, also known as CMT2D and Silver syndrome (SS) are rare phenotypically overlapping diseases which can be caused by mutations in the Berardinelli-Seip Congenital Lipodystrophy 2 (BSCL2) and in the glycyl-tRNA synthetase encoding (GARS) genes. Mutations in the heat-shock proteins HSPB1 and HSPB8 can cause related distal hereditary motor neuropathies (dHMN) and are considered candidates for dHMN-V, CMT2, and SS.

DESIGN

To define the frequency and distribution of mutations in the GARS, BSCL2, HSPB1 and HSPB8 genes we screened 33 unrelated sporadic and familial patients diagnosed as either dHMN-V, CMT2D or SS. Exon 3 of the BSCL2 gene was screened in further 69 individuals with an unclassified dHMN phenotype or diagnosed as hereditary spastic paraplegia (HSP) complicated by pure motor neuropathy.

RESULTS

Four patients diagnosed with dHMN-V or SS carried known heterozygous BSCL2 mutations (N88S and S90L). In one dHMN-V patient we detected a putative GARS mutation (A57V). No mutations were detected in HSPB1 and HSPB8. The diagnostic yield gained in the series of 33 probands was 12% for BSCL2 mutations and 3% for GARS mutations. In the series of unclassified dHMN and complicated HSP cases no mutations were found.

CONCLUSIONS

Our data confirm that most likely only two mutations (N88S, S90L) in exon 3 of BSCL2 may lead to dHMN-V or SS phenotypes. Mutations in GARS, HSPB1 and HSPB8. are not a common cause of dHMN-V, SS and CMT2D. We would therefore suggest that a genetic testing of dHMN-V and SS patients should begin with screening of exon 3 of the BSCL2 gene. Screening of the GARS gene is useful in patients with CMT2 with predominant hand involvement and dHMN-V. The rather low frequencies of BSCL2, GARS, HSPB1 and HSPB8 mutations in dHMN-V, CMT2D and SS patients strongly point to further genetic heterogeneity of these related disorders.

[Hepatomioneuropathy secondary to mitochondrial DNA depletion]

INTRODUCTION

Mitochondrial DNA depletion (mtDNA) is an highly heterogeneous condition characterized by a decreased number of mtDNA copies.

CASE REPORT

The patient is a 22-month-old girl with generalized hypotonia, marked weakness, respiratory failure, arterial hypertension, hyperlactacidemia, hepatosplenomegaly and mild hypertransaminasemia without hepatic failure neither hypoketotic hypoglycemia. Electromyographic findings were consistent with neuromyopathy and muscle biopsy suggested a neurogenic atrophy. Electron microscopy revealed lipid droplets, subsarcolemmal accumulation of mitochondrias and glycogen granules. Respiratory chain enzime activities were normal. Genetic study in muscle showed mtDNA depletion, and the diagnosis of spinal muscular atrophy caused by survival motoneuron gene deletion was excluded.

CONCLUSIONS

This case might be a novel phenotype of mtDNA depletion which could be named hepatomioneuropatyc form. A normal result of respiratory chain enzimes in muscle doesn't excluded mtDNA depletion.

Inherited focal, episodic neuropathies: hereditary neuropathy with liability to pressure palsies and hereditary neuralgic amyotrophy

Hereditary neuropathy with liability to pressure palsies (HNPP; also called tomaculous neuropathy) is an autosomal-dominant disorder that produces a painless episodic, recurrent, focal demyelinating neuropathy. HNPP generally develops during adolescence, and may cause attacks of numbness, muscular weakness, and atrophy. Peroneal palsies, carpal tunnel syndrome, and other entrapment neuropathies may be frequent manifestations of HNPP. Motor and sensory nerve conduction velocities may be reduced in clinically affected patients, as well as in asymptomatic gene carriers. The histopathological changes observed in peripheral nerves of HNPP patients include segmental demyelination and tomaculous or "sausage-like" formations. Mild overlap of clinical features with Charcot-Marie-Tooth (CMT) disease type 1 (CMT1) may lead patients with HNPP to be misdiagnosed as having CMT1. HNPP and CMT1 are both demyelinating neuropathies, however, their clinical, pathological, and electrophysiological features are quite distinct. HNPP is most frequently associated with a 1.4-Mb pair deletion on chromosome 17p12. A duplication of the identical region leads to CMT1A. Both HNPP and CMT1A result from a dosage effect of the PMP22 gene, which is contained within the deleted/duplicated region. This is reflected in reduced mRNA and protein levels in sural nerve biopsy samples from HNPP patients. Treatment for HNPP consists of preventative and symptom-easing measures. Hereditary neuralgic amyotrophy (HNA; also called familial brachial plexus neuropathy) is an autosomal-dominant disorder causing episodes of paralysis and muscle weakness initiated by severe pain. Individuals with HNA may suffer repeated episodes of intense pain, paralysis, and sensory disturbances in an affected limb. The onset of HNA is at birth or later in childhood with prognosis for recovery usually favorable; however, persons with HNA may have permanent residual neurological dysfunction following attack(s). Episodes are often triggered by infections, immunizations, the puerperium, and stress. Electrophysiological studies show normal or mildly prolonged motor nerve conduction velocities distal to the affected brachial plexus. Pathological studies have found axonal degeneration in nerves examined distal to the plexus abnormality. In some HNA pedigrees there are characteristic facial features, including hypotelorism. The prognosis for recovery of normal function of affected limbs in HNA is good, although recurrent episodes may cause residual deficits. HNA is genetically linked to chromosome 17q25, where mutations in the septin-9 (SEPT9) gene have been found.

A Japanese family with early-onset ataxia with motor and sensory neuropathy

We report the case of a Japanese family with hereditary ataxia with peripheral neuropathy. Three affected siblings from this family exhibited very similar clinical features: teenage-onset, slowly progressive ataxia, followed by distal weakness, which developed after the age of 30 years. Magnetic resonance imaging studies showed marked atrophy in the cerebellar hemisphere and vermis, and a sural nerve biopsy revealed a marked reduction in the number of both myelinated and unmyelinated fibers. All patients exhibited hyperglutamatemia, but serum levels of albumin and lipid were normal. The clinicopathological and biochemical features of these cases suggest that they form a distinct entity of autosomal recessive hereditary ataxia with peripheral neuropathy.

Molecular genetics of hereditary sensory neuropathies

Hereditary sensory neuropathies (HSN), also known as hereditary sensory and autonomic neuropathies (HSAN), are a clinically and genetically heterogeneous group of disorders. They are caused by neuronal atrophy and degeneration, predominantly affecting peripheral sensory and autonomic neurons. Both congenital and juvenile to adulthood onset is possible. Currently, the classification of the HSN depends on the mode of inheritance, age at onset, and clinical presentation. Hallmark features are progressive sensory loss, chronic skin ulcers, and other skin abnormalities. Spontaneous fractures and neuropathic arthropathy are frequent complications and often necessitate amputations. Autonomic features vary between different subgroups. Distal muscle weakness and wasting may be present and is sometimes so prominent that it becomes difficult to distinguish HSN from Charcot-Marie-Tooth syndrome. Recent major advances in molecular genetics have led to the identification of seven gene loci and six-disease causing genes for autosomal-dominant and autosomal-recessive HSN. These genes have been shown to play roles in lipid metabolism and the regulation of intracellular vesicular transport, but also a presumptive transcriptional regulator, a nerve growth factor receptor, and a nerve growth factor have been described among the causative genes in HSN. Nevertheless, it remains unclear how mutations in the known genes lead to the phenotype of HSN. In this review, we summarize the recent progress of the molecular genetics of the HSN and the implicated genes.

Expression of CD28-related costimulatory molecule and its ligand in inflammatory neuropathies

BACKGROUND

Activation of effector T lymphocytes, mediated in part by costimulatory molecules, is an important mechanism in the pathogenesis of immune-mediated diseases of the peripheral nervous system (PNS).

OBJECTIVE

To analyze the expression and distribution pattern of the inducible costimulator (ICOS), a recently identified costimulatory molecule implicated in T-cell activation, and its unique ligand (ICOS-L), in inflammatory disorders of the PNS.

METHODS

We studied RNA and protein expression in sural nerve biopsy specimens from patients with Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and vasculitic neuropathy (VN) vs patients with hereditary neuropathies (HNs) serving as a noninflammatory control using reverse-transcriptase PCR and immunohistochemistry. In addition, in vitro analysis was performed by flow cytometry.

RESULTS

ICOS and ICOS-L mRNA was found to be significantly upregulated in samples from patients with GBS, CIDP, and VN compared to HNs. Immunohistochemistry identified T lymphocytes as the cellular source of ICOS, whereas macrophages expressed the corresponding ligand ICOS-L. Further analysis revealed that the distribution of ICOS-expressing T cells did not differ between acute and chronic inflamed PNS diseases. Correspondingly, the expression pattern of ICOS-L was similar in the inflamed tissues but differed significantly when compared to HNs.

CONCLUSIONS

Inducible costimulator, expressed by T lymphocytes, and inducible costimulator ligand, expressed by macrophages within the peripheral nerve, might not only be relevant in inducing an acute immune response but might also be critically involved in perpetuating inflammation in chronically immune-mediated disorders of the peripheral nervous system.

Early-onset hereditary neuropathy with liability to pressure palsy

The clinical onset of hereditary neuropathy with liability to pressure palsy (HNPP) in childhood is rarely reported. On the basis of a 5-year-old affected patient, we reviewed the cases reported in the literature to evaluate the clinical and genetic characteristics of patients with an early onset (<10 years) of HNPP.

The Inherited Neuropathies

Neuropathy is one of the most common referrals to neurologic clinics. Patients often undergo extensive testing for acquired etiologies; inherited causes are common. Increasingly, genetic causes are becoming known and commercial testing available. The rate of recent discovery has been rapid and relates to the extent of single gene disorders of nerve, the ease of peripheral nervous system functional examination, and readily accessible pathologic tissue. Foremost in the rate of recent discoveries is the work and tools of the human genome project. the rapidity of the ongoing discovery requires clinicians to be familiar with molecular biologic discoveries and consider wisely which testing should be performed.

[Hereditary motor and sensory Lom-neuropathy--first Hungarian case report]

Hereditary motor and sensory neuropathy-Lom is an autosomal recessive disorder of the peripheral nervous system, which occurs only in the european Roma population. The symptoms start in the first decade with slowly progressive gait disturbance, weakness and wasting of distal upper extremity muscles, joint deformities and hearing loss develop later in the second and third decades. This disorder is caused by a homozygous missense mutation of the NDRG1 gene, located in the 8q24 region. The Schwann cell dysfunction is most probably caused by altered lipid metabolism as a consequence of the NDRG1 mutation. Molecular genetic testing can be a first diagnostic step among roma individuals showing a Lom neuropathy phenotype, making evaluation of such patients and also genetic counselling faster and easier. Screening for hereditary neuromuscular disorders in this genetically isolated community may become an important public health issue in the near future.

Autosomal-recessive and X-linked forms of hereditary motor and sensory neuropathy in childhood

The hereditary motor and sensory neuropathies (HMSNs, Charcot-Marie-Tooth neuropathies) are the most common degenerative disorders of the peripheral nervous system. In recent years a dramatic expansion has occurred in our understanding of the molecular basis and cell biology of the recessively inherited demyelinating and axonal neuropathies, with delineation of a number of new neuropathies. Mutations in some genes cause a wide variety of clinical, neurophysiologic, and pathologic phenotypes, rendering diagnosis difficult. The X-linked forms of HMSN represent at least 10%-15% of all HMSNs and have an expanded disease spectrum including demyelinating, intermediate, and axonal neuropathies, transient central nervous system (CNS) dysfunction, mental retardation, and hearing loss. This review presents an overview of the recessive and X-linked forms of HMSN observed in childhood, with particular reference to disease phenotype and neurophysiologic and pathologic abnormalities suggestive of specific diagnoses. These findings can be used by the clinician to formulate a differential diagnosis and guide targeted genetic testing.

Macrophage colony stimulating factor is a crucial factor for the intrinsic macrophage response in mice heterozygously deficient for the myelin protein P0

Mouse mutants heterozygously deficient for the myelin protein P0 (P0+/-) resemble certain forms of human hereditary neuropathies. Endoneurial macrophages of intrinsic origin are intimately involved in the pathogenesis of the demyelinating neuropathy in these mutants. We have previously shown that deficiency for macrophage colony stimulating factor (M-CSF) prevents an increase of the number of endoneurial macrophages and alleviates the mutants' demyelinating phenotype. The aim of this study was to investigate which population of endoneurial macrophages - long-term resident macrophages or recently infiltrated macrophages - is affected by M-CSF deficiency. For this purpose, we generated bone marrow chimeric mice by transplanting GFP+ bone marrow into P0 mutants (P0+/-) and P0 mutants that lack M-CSF (P0+/- mcsf-op). This enabled us to discriminate recently infiltrated short-term resident GFP+ macrophages from long-term resident GFP- macrophages. Three months after bone marrow transplantation, P0+/- mice expressing M-CSF showed a substantial upregulation and activation of both GFP- and GFP+ macrophages in femoral nerves when compared to P0+/+ mice. In contrast, in P0+/- mcsf-op mutants, both GFP- and GFP+ macrophages did not substantially increase. Only small numbers of GFP+ but no GFP- macrophages were activated and phagocytosed myelin in chimeric P0+/- mcsf-op mutants, possibly reflecting recent activation outside the endoneurium before entering the nerve. Our findings demonstrate that M-CSF is crucial for the activation, in situ increase and myelin phagocytosis of both long-term and short-term resident endoneurial macrophages in P0+/- myelin mutants. M-CSF is, therefore, considered as a target candidate for therapeutic strategies to treat human demyelinating neuropathies.

Bilateral hand amyotrophy with PMP-22 gene deletion

Hereditary neuropathy with liability to pressure palsies (HNPP) phenotypes are heterogeneous. We report the case of a 52-year-old woman without medical history, who complained of bilateral hand weakness suggestive first of a motor neuron disorder. The presence of a diffuse predominant distal demyelinating neuropathy suggested a deletion of PMP-22 gene, which was confirmed by genetic analysis. This case report underlines a novel phenotype related to the deletion of PMP-22 gene.