Hepatitis C virus infection and myositis: a polymerase chain reaction study

Muscle biopsy tissue from a patient with chronic hepatitis, who was hepatitis C virus (HCV) positive and showed slight weakness of the right arm and leg associated with increased serum creatine kinase levels, was studied using immunocytochemical and polymerase chain reaction (PCR) techniques. Muscle biopsy showed changes compatible with an inflammatory myopathy. Immunohistochemical studies included the use of monoclonal antibodies against human T lymphocytes, macrophages, immunoglobulins, major histocompatibility complex class I molecules (MHC-I), and the neoantigens of the terminal C5b-9 complement membrane attack complex (MAC). In addition to confirming the potential importance of cytotoxic T cells and MHC-I antigen expression in inducing muscle pathology, we demonstrated MAC deposition and the presence of HCV-RNA in the muscle of our patient, suggesting that direct involvement of the virus leading to complement activation might be important in inducing muscle damage.

Inheritance of a 38-kb fragment in apparently sporadic facioscapulohumeral muscular dystrophy

Facioscapulohumeral dystrophy (FSHD) is an autosomal-dominant muscular disorder associated with a short (<35 kb) EcoRI/BlnI fragment resulting from deletion of an integral number of units of a 3.3-kb repeat located at 4q35. In this study, we determined fragment sizes separated by pulsed-field gel electrophoresis in a patient with an apparently sporadic case of FSHD and in his healthy family members. A 38-kb fragment was detected in the proband, in his older brother, and in their father. This finding prompted a clinical reevaluation of the father and brother. A subclinical phenotype restricted to abdominal muscle weakness was detected, and serum creatine kinase values were found to be elevated in both. The proband's brother also showed evidence of an independently occurring subtelomeric rearrangement of 4q35, which normally occurs in about 20% of the population. The identification of a "borderline" 38-kb EcoRI/BlnI fragment in an affected subject and his very mildly affected relatives extends the size range of disease alleles and expands existing data on the variable intrafamilial expressivity of FSHD. This study highlights the importance of a careful molecular and clinical analysis extended to family members of apparently sporadic cases with larger EcoRI/BlnI fragments for accurate diagnosis and appropriate genetic counseling in FSHD.

Ataxin 1 and ataxin 3 in neuronal intranuclear inclusion disease

Neuronal intranuclear inclusion disease (NIID) is a multisystem neurodegenerative disorder characterized by large intranuclear aggregates in neurons of the central and peripheral nervous system. These ubiquitinated intranuclear inclusions are morphologically similar to the intraneuronal aggregates that have been identified in the CAG/polyglutamine expansion diseases. As rare aggregates in NIID contain a polyglutamine epitope, we further investigated the relationship between this disease and the CAG/polyglutamine expansion diseases. Here, we show that ataxin 1 and ataxin 3 proteins are recruited into aggregates in NIID in the absence of a CAG expansion in the SCA1 and SCA3 genes. These data support an association of NIID with the polyglutamine disorders and provide evidence of in vivo recruitment of proteins with polyglutamine tracts into intraneuronal aggregates.

Decreased expression of laminin beta 1 in chromosome 21-linked Bethlem myopathy

Muscle biopsies of four patients affected by chromosome 21-linked Bethlem myopathy were investigated by means of immunohistochemistry, with monoclonal antibodies for laminin chains, dystrophin and dystrophin associated glycoproteins. The objective of this study was to determine whether an altered molecular structure of collagen type VI, characteristic of Bethlem myopathy, could influence the expression of the protein complex linking the extracellular matrix with the subsarcolemmal cytoskeleton. Normal expression of all proteins was found except for laminin beta 1, along with an age related progressive deficiency of this protein in the muscle fibre basal lamina. This study shows that Bethlem myopathy linked to chromosome 21 is associated with a secondary decrease in laminin beta 1 expression.

Detection of beta-A4 amyloid and its precursor protein in the muscle of a patient with juvenile neuronal ceroid lipofuscinosis (Spielmeyer-Vogt-Sjögren)

Muscle biopsy tissue from a patient affected by the juvenile form of neuronal ceroid lipofuscinosis (NCL) was studied immunohistochemically using antibodies to beta-amyloid peptide and amyloid precursor protein. Positive reaction in muscle was specifically localized to autophagic vacuoles and blood vessel walls. Increased acid phosphatase reaction suggested enhanced lysosomal activity. We hypothesize that beta-amyloid is deposited in NCL muscle by a lysosomal mechanism similar to that proposed in other disorders involving beta-amyloid.

Acute inflammatory neuropathy in Charcot-Marie-Tooth disease

The authors report an association between acute inflammatory neuropathy and previously undiagnosed Charcot-Marie-Tooth 1A disease in a 15-year-old girl. Sural nerve biopsy study showed hypertrophic neuropathy with endoneurial infiltrates of macrophages and lymphocytes. This association may be coincidental, but a particular susceptibility to damage of these peripheral nerves cannot be excluded. This report confirms the importance of pes cavus as a sign of long-standing sensorimotor neuropathy.

Identification and characterization of a highly conserved protein absent in the Alport syndrome (A), mental retardation (M), midface hypoplasia (M), and elliptocytosis (E) contiguous gene deletion syndrome (AMME)

We recently described a novel contiguous gene deletion syndrome (AMME) in Xq22.3 that includes Alport syndrome (A), mental retardation (M), midface hypoplasia (M), and elliptocytosis (E). While the Alport syndrome is due to deletion of the COL4A5 gene, no other genes are known in the region with the exception of our recent finding of the FACL4 gene. In our effort to isolate additional genes from the deleted region, we have identified the gene named AMMECR1 (Alport syndrome, mental retardation, midface hypoplasia, and elliptocytosis chromosomal region gene 1). RACE experiments and screening of cDNA libraries enabled us to obtain the entire ORF of the gene (1002 bp) followed by about 2 kb of 3'UTR. AMMECR1 is composed of six exons, shows a ubiquitous 6.5-kb transcript, and codes for a protein with a molecular mass of 35.5 kDa. Sequence analysis revealed that this gene is conserved in several species ranging from Caenorhabditis elegans and yeast to micro-organisms. Exon 2 of AMMECR1 encodes a domain consisting of six amino acids identically conserved throughout the course of evolution and whose function is as yet unknown. Analysis of the predicted protein product using ExPAsy tools raises the possibility that the gene may code for a regulatory factor potentially involved in the development of AMME contiguous gene deletion syndrome.

Ultrastructural study of enteric ganglia in three patients with Rett syndrome

In order to verify whether a pseudo-obstruction syndrome was associated with morphological changes in enteric ganglia, we performed an ultrastructural study on rectal biopsy specimens in three patients with Rett syndrome. Features of enteric neurons, detected to a different extent in all three biopsy specimens, included an abnormal dilatation of endoplasmic reticulum with a disorganization of cisternae of the Golgi apparatus, and masses of unidentified electron-dense granulo-filamentous material, probably of lipidic origin, observed in the perikaryon. Large electron-lucent membrane-bound vacuoles were found mostly within satellite glial cells. Sometimes, the axon terminals were swollen and showed intraxonal vacuolization. We conclude that the reported findings do not represent a specific sign of degeneration and do not constitute a significant morphological marker of disease.

Immunofluorescence study of a muscle biopsy from a 1-year-old patient with Walker-Warburg syndrome

A previous study of two patients with Walker-Warburg syndrome (WWS) showed a severe deficiency of the extracellular matrix protein laminin beta2 chain and alpha-sarcoglycan (adhalin) in skeletal muscle fibers. More recently, however, other researchers have shown that in their WWS patients the expression of the laminin beta2 chain and alpha-sarcoglycan was normal. Here we describe a 1-year-old boy affected with WWS. We performed immunohistochemical studies on a muscle biopsy from this patient using monoclonal antibodies against dystrophin, dystrophin-associated glycoproteins and several proteins of the extracellular matrix. We confirm previously reports as far as the diminished expression of laminin beta2 chain and alpha-sarcoglycan is concerned. The expression of some other laminins was unusual, whereas the expression of collagen IV and VI was normal. These results suggest that complex syndromes like WWS are quite heterogeneous, although they might represent variant expressions of a single pathological entity.

Association in the same patient of autosomal dominant progressive external ophthalmoplegia with multiple mtDNA deletions and X-linked ichthyosis: clinical, biochemical, histological, submicroscopic and molecular genetic study

Autosomal dominant chronic progressive external ophthalmoplegia (AdPEO) is a muscle mitochondrial disorder due to multiple large scale rearrangements of the mitochondrial DNA. This disorder is probably due to a nuclear defect which causes genetic instability or an impairment in the replication of mitochondrial DNA. X-linked ichthyosis (XLI) is a skin disorder caused by a deletion in the steroid-sulphatase gene. Here we report the clinical, biochemical, morphologic and molecular genetic findings in a patient affected by both AdPEO, inherited by the father, and steroid-sulphatase-deficiency, inherited by the mother. The association in the same patient of the two inherited diseases is merely casual and does not seem to influence the phenotypic expression of the two diseases.

CAG repeat expansion in an italian family with spinocerebellar ataxia type 2 (SCA2): a clinical and genetic study

We report an Italian family in which molecular genetic analysis showed expansion of CAG repeats indicative of the SCA2 genotype. This family confirms that ataxia, ophthalmoparesis and sensory peripheral neuropathy are the salient features of the SCA2 phenotype. In the present cases, early onset and mental deterioration were important additional findings. Nerve biopsy findings were compatible with a chronic axonopathy. We found a direct correlation between length of triplet expansion and severity of the clinical symptoms. Of particular interest is the late-onset phenotypical expression in a patient with 34 repeats.

Neuronal intranuclear inclusion disease: neuropathologic study of a case

We report neuropathological findings in a 22-year-old man affected with neuronal intranuclear inclusion disease. The inclusions affected to different extents the various structures of the central nervous system, being more numerous in cerebral cortex, inferior olives, hypoglossal and oculomotor nuclei. They ultrastructurally differed from Marinesco bodies. In the neurons of the substantia nigra, we occasionally observed intranuclear inclusions resembling the so-called rodlets of Roncoroni. We did not observe inclusions in the extraneuronal tissues. There was no apparent correlation between frequency of the inclusions and neuronal loss. Intranuclear inclusions were found in many morphologically normal neurons. We suggest that the intranuclear inclusions are the marker of a distinctive disorder, even though their role in neuronal degeneration remains to be clarified.

Giant axonal neuropathy with subclinical involvement of the central nervous system: case report

The case of a 17-year-old girl with slowly progressive sensory-motor neuropathy is described. Sural nerve biopsy showed abnormally enlarged exons filled with neurofilaments. Neurofilament accumulation was limited to the axons and was not found in other cells of the skin or peripheral nerve. The patient showed EEG and brain MRI abnormalities, but there was no clinical evidence of central nervous system involvement. Although these findings suggest an atypical attenuated form of giant axonal neuropathy, a new nosological entity cannot be excluded.

Hereditary motor and sensory neuropathy Lom type in an Italian Gypsy family

We describe a form of hereditary motor and sensory neuropathy (HMSN) affecting four siblings in an Italian family of Gypsy ethnic origin with both clinical and pathological findings very reminiscent of the HMSN Lom type (HMSNL), recently described in a group of Bulgarian Gypsies. Genetic analysis demonstrated linkage to chromosome 8q24 and conserved haplotypes in the HMSNL region, thus confirming that this is the first Gypsy family outside the Balkans suffering from the same disorder.

Juvenile Leigh syndrome with protracted course presenting as chronic sensory motor neuropathy, ataxia, deafness and retinitis pigmentosa: a clinicopathological report

We herein describe a male patient who died at 37 years of age, after having suffered from a slowly progressive syndrome of chronic sensory motor neuropathy, deafness, retinitis pigmentosa and ataxia. The neuropathological study showed symmetric areas of necrosis and demyelination affecting the cerebellum and brainstem. The type of lesion was consistent with the characteristics of Leigh Syndrome. On the basis of the histology of the lesions, we believe that they appeared only a few months before the death of the patient. We underline the atypical clinical picture and suggest that, in certain cases, brain MRI may not be a reliable diagnostic tool.

Schnyder corneal crystalline dystrophy: description of a new family with evidence of abnormal lipid storage in skin fibroblasts

Schnyder corneal crystalline dystrophy (SCCD) comprises corneal opacities often associated with precocious arcus senilis and genua valga. The metabolic defect seems to be related to abnormal lipid storage in the central part of the cornea, especially the anterior stroma, consisting mainly of nonesterified cholesterol. Plasma lipid levels are not always increased suggesting that the disease may be due to abnormal lipid metabolism limited to the cornea. We observed a family with typical SCCD, in 1 case associated with mental retardation and mild cerebellar hypoplasia. Results of serum lipid analysis of all patients were normal. Ultrastructural study of a skin biopsy specimen and fibroblast pellet showed membrane-bound spherical vacuoles containing lipid material. Cultured fibroblasts stained by filipin, a fluorescent probe that specifically binds unesterified cholesterol, showed abnormal cytoplasmic fluorescent material, suggesting abnormal cholesterol metabolism. The presence of neurological impairment, associated with SCCD in 1 of our cases, may be regarded as coincidental. Evidence of storage lipids in skin and cultured fibroblasts suggests that the disorder of intracellular cholesterol metabolism is not limited to the cornea and that skin biopsy may be a useful method to confirm the diagnosis.

Localization of laminin alpha 2 chain in normal human central nervous system: an immunofluorescence and ultrastructural study

Recently, a rare form of congenital muscular dystrophy has been shown to be associated with a deficiency of laminin alpha 2 chain, a tissue-specific component of the basal lamina. Besides muscular dystrophy, children affected with this disorder also show electrophysiological and magnetic resonance imaging evidence of white matter involvement in the central nervous system (CNS). We have studied the precise localization of laminin alpha 2 chain in normal human brain, using specific electron microscopic techniques including thin-section fracture labeling and cryoultramicrotomy, in parallel with immunohistochemical techniques. We found that this laminin chain was localized to the basal lamina of all cerebral blood vessels, whereas blood vessels of the choroid plexus did not show any reaction. No positive reaction was found in meningeal blood vessels either. We hypothesize that in normal brain, laminin alpha 2 may be important for the selective filtration capability of the blood-brain barrier. The lack of laminin alpha 2 in cerebral vessels of children with laminin alpha 2-deficient congenital muscular dystrophy may cause impaired selective filtration, leading to leakage of plasma components and damage to the CNS. Further studies should be performed on patients affected by congenital muscular dystrophy associated with laminin alpha 2 deficiency to test this hypothesis.

Chorea-acanthocytosis: genetic linkage to chromosome 9q21

Chorea-acanthocytosis (CHAC) is a rare autosomal recessive disorder characterized by progressive neurodegeneration and unusual red-cell morphology (acanthocytosis), with onset in the third to fifth decade of life. Neurological impairment with acanthocytosis (neuroacanthocytosis) also is seen in abetalipoproteinemia and X-linked McLeod syndrome. Whereas the molecular etiology of McLeod syndrome has been defined (Ho et al. 1994), that of CHAC is still unknown. In the absence of cytogenetic rearrangements, we initiated a genomewide scan for linkage in 11 families, segregating for CHAC, who are of diverse geographical origin. We report here that the disease is linked, in all families, to a 6-cM region of chromosome 9q21 that is flanked by the recombinant markers GATA89a11 and D9S1843. A maximum two-point LOD score of 7.1 (theta = .00) for D9S1867 was achieved, and the linked region has been confirmed by homozygosity-by-descent, in offspring from inbred families. These findings provide strong evidence for the involvement of a single locus for CHAC and are the first step in positional cloning of the disease gene.

Palpebral ptosis and muscle fatiguability associated with perineurial cell ensheathment of muscle fibers: a new disease of the neuromuscular junction?

Perineurial cell ensheathment of muscle fibers has been reported only in one patient. Here we describe a new case with identical morphologic features and a similar, but milder clinical course characterized by progressive muscle weakness and bilateral palpebral ptosis. EMG examination (including repetitive stimulation) and antibodies against acetylcholine receptors were normal. Muscle biopsy revealed several muscle fibers encircled by stratified rings of homogeneous material in which elongated nuclei were visible; this material was positively stained by antibodies directed at epithelial membrane antigen. On ultrastructural examination these encircling-fiber spirals had the characteristics of perineurial cells. It is not clear yet whether perineurial cell ensheathment of muscle fibers is an occasional feature, or whether it has a pathogenetic role in the clinical picture of both cases. The perineurial sheaths might alter the correct neuromuscular transmission mimicking a myasthenia-like disease, either by interfering with the neuromuscular junction, or by changing the microenvironment, and, thus, altering the general excitability of the muscle fibers.

Detection of Borrelia burgdorferi DNA and complement membrane attack complex deposits in the sural nerve of a patient with chronic polyneuropathy and tertiary Lyme disease

We report a patient who developed a chronic sensory-motor polyneuropathy and a progressive myelopathy 4 years after a tick bite. An increased serum antibody titer to Borrelia burgdorferi suggested a diagnosis of Lyme neuroborreliosis, although a concomitant cervical spondylosis probably contributed to spinal cord damage. Treatment with ceftriaxone resulted in a marked improvement of neuropathic symptoms, providing indirect evidence of spirochetal infection. Search for B. burgdorferi DNA by polymerase chain reaction amplification on sural nerve confirmed the diagnosis, demonstrating that the spirochete localized in the peripheral nervous system. The presence of complement membrane attack complex deposits and macrophage infiltrates around epineurial vessels and within the endoneurium suggests that the neuropathy in our patient was immune-mediated.

A rare association of myasthenia gravis and mitochondrial myopathy: a clinical, biochemical and morphologic study of one case

Myasthenia gravis and mitochondrial myopathy may present with similar clinical symptoms as inconstant palpebral ptosis, ophthalmoparesis, and muscle weakness. A few case initially diagnosed as myasthenia gravis by a positive decremental response on EMG and successful anticholinesterase therapy revealed to be affected by mitochondrial disease. We report a new case initially found to be affected by myasthenia gravis in whom muscle biopsy, performed because of symptom worsening, disclosed a mitochondrial myopathy. It is not clear if the association of mitochondrial myopathy and myasthenia gravis is coincidental or if there is a pathogenic link between the two pathologies. We suggest that muscle biopsy should be performed in cases with atypical myasthenia gravis signs.