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The authors report a 71-year-old woman with limb-girdle muscular dystrophy (LGMD) associated with an R27Q mutation in the CAV3 gene. Immunohistochemistry showed a >90% reduction of caveolin-3 on the sarcolemma by western blot, and anti-dysferlin immunoreactivity was reduced. This case emphasizes that an R27Q missense mutation in the CAV3 gene can lead to various clinical phenotypes including hyperCKemia, rippling muscle disease, distal myopathy, and LGMD1C.

Over the past 10 years, the impact of modern microscopic pathology and molecular genetics on the knowledge of myopathies has been enormous. Dysferlinopathy is a good example. Dysferlin is a surface membrane protein without homology with known mammalian protein excepted otoferlin. It is encoded by a gene on chromosome 2. Miyoshi myopathy and limb girdle muscular dystrophy 2B have been reported to arise from defects in the same genetic locus (chromosome 2p 13). Some personal different examples are presented with typical features, high level of creatine kinase. Gene mutations, immunoblot and immunohistochemistry allow the diagnosis. Three clinical phenotypes are separated: distal myopathy, proximal myopathy, entire lower limbs posterior compartment amyotrophy. Structural changes are mild. Inflammation is not unusual and leads to the diagnosis of polymyositis. There are no correlation genotype-phenotype.

The clinico-pathological features of 17 patients displaying a myopathy with lobulated (trabeculated) fibers are reported. All these patients had a limb girdle phenotype and at least 20% of lobulated fibers in their muscle biopsies. There were ten females and seven males. The onset of symptoms ranged from 2 to 55 years (mean 24). The average age at the time of muscle biopsy was 39 (range 3-63). Interestingly, in six patients, high prevalence of lobulated fibers was observed at the second biopsy only, performed on average 11 years after the first or in another muscle. Six patients had a suggestively positive family history. Facial weakness was noted in two patients (genetic study confirmed FSH dystrophy). The course and the severity of weakness varied from one patient to another. Immunohistochemistry and Western blot analyses revealed one Duchenne carrier, one alpha-sarcoglycanopathy, no dysferlinopathy and four calpain deficiencies (including one patient with FSH dystrophy), but SSCP revealed mutation in the calpain gene in only one of the patients. These results show that (1) myopathies with lobulated fibers are clinically and genetically heterogeneous, (2) lack of calpain expression by Western blot analysis is not always associated with null mutation, (3) a molecular diagnosis is made in less than 40% of myopathy with lobulated fibers, (4) when observed, lobulated fibers are most prominent in proximal muscles and require time to appear.

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disorder for which no candidate gene has yet been identified. The gene corresponding to one of the novel human cDNAs that we cloned on the basis of a muscle restricted expression pattern [Piétu G, Alibert O, Guichard B, et al. Genome Res 1996;6:492-503] was mapped in the region of the FSHD1A genetic locus, i.e. one of the loci involved in this muscular dystrophy. The corresponding encoded protein contains a PDZ and a LIM domain, two protein-protein interaction domains, and was very recently shown to bind alpha-actinin-2 and was named ALP (actinin-associated LIM protein) [Xia H, Winokur S, Kuo W, Altherr M, Bredt D. J Cell Biol 1997;139:507-515]. We raised a specific polyclonal anti-ALP serum against an ALP recombinant polypeptide to evaluate the size, level of expression and subcellular localization of ALP in three patients, clearly diagnosed with FSHD disease. Quantitative or qualitative alterations of ALP expression have not been detected in any of them, thus prompting us to exclude ALP as a FSHD gene candidate.

Muscles from Becker muscular dystrophy (BMD) and Duchenne muscular dystrophy (DMD) patients were analysed using monoclonal and polyclonal antibodies raised against different regions of the dystrophin molecule. On blot, two of the antibodies detected a protein of Mr 400K in muscle extracts from all patients, including a BMD patient with a deletion which spanned more than 40% of the central rod domain of the Xp21 encoded dystrophin. Immunocytochemical labelling of tissue sections from the same patients showed that the same two antibodies labelled a protein at the surface membrane of smooth muscle fibers in blood vessels of both BMD and DMD muscles. Thus we have demonstrated a 400K blood vessel-associated protein, which is immunologically homologous with dystrophin, for at least two epitopes from the carboxy terminal and the central rod domains must be encoded by another gene than the dystrophin gene.

Four patients with typical signs of congenital muscular dystrophy (C.M.D.), as described in the literature, are reported. In two young sisters born from consanguineous parents the presenting signs were severe congenital hypotonia in one and hypotonia with arthrogryposis in the other. The two other cases were adult patients with a long standing disease, the onset haring been marked by a transient neonatal hypotonia in one and by a congenital torticollis in the other. All 4 patients had progressively increasing muscle retractions, with absent reflexes in three. C.P.K. was moderately increased in all patients. Electromyography demonstrated myopathic abnormalities in 3 cases, associated in 2 cases with misleading pseudo-neurogenic signs. MUscle biopsy showed non specific changes compatible with muscular dystrophy: fibrosis and/or fat involution was marked in all cases, while necrosis of fibers was rarely observed. Histoenzymology and morphometry confirmed the absence of lesion specificity and their results were variable from case to case. A review of 92 published cases demonstrated that the course of the disease is very variable. A fatal outcome occurs in 15% of cases, while the affection becomes worse or remains stable with about the same frequency. A progressive worsening of muscle retractions is a characteristic finding in C.M.D. Genetically, most cases are of recessive autosomic. The current nosology of C.M.D. is probably inadequate, the clinical picture including cases that are likely to be due to different mechanisms that 2 present methods of investigation cannot demonstrate.

Very few authenticated cases of benign muscular dystrophy affecting mainly the girdles and of dominant autosomal inheritance have been documented. Two families were seen with this type of transmission, and certain common characteristics noted: proximal weakness and amyotrophy, frequency of muscle contractures, mainly distal, true calf hypertrophy, slow progression and benign nature and finally a fairly uniform semiology in the same family, an atypical finding in dominant autosomal hereditary disease.

Reservations exist as to the validity of the concept of distal myopathies, and confirmed cases of this affection have rarely been reported. A scandinavian patient with the probable familial type of the disorder was studied by electrophysiological and histological examinations. Clinical criteria and differential diagnosis of this variety of muscular dystrophy are discussed, and a critical review of cases reported in the literature as distal myopathies is conducted. Very few of them are able to stand up to this criticism.

Seventy-five patients with a variety of muscular dystrophies were studied using computed tomography (CT). At least 11 slices were taken in each patient, from the forearm to the lower leg. Sufficient information was obtained to provide some CT characteristics of several dystrophies, including Duchenne muscular dystrophy, facioscapulohumeral syndrome, limb-girdle muscle myopathies, and myopathic dystrophies. CT promises to be of increasing value in these areas in the future.

The muscular disease described by Ullrich (1930) is no longer included in classifications of neuromuscular disorders. A typical case is reported and 15 documented cases have been found in the German and Japanese literature. The clinical picture associates, paradoxically, retraction of proximal muscles and hyperlaxity of distal muscles and joints. The dystrophic nature of the disease is uncertain.

Sural nerve biopsies from 13 unselected myotonic dystrophy patients and 6 normal controls were studied morphometrically. The myelinated fiber density was reduced in 11 of the 13 myotonic dystrophy patients, with preferential loss of large myelinated fibers. Unmyelinated fiber densities and diameters were normal. Teased fiber studies commonly revealed focal areas of remyelination and abnormal wrinkling of the myelin sheath. Measurement of internodal length disclosed features of both axonal regeneration and focal demyelination-remyelination. These findings are consistent with a chronic axonopathy of moderate severity, possibly due to axonal atrophy.

Quadricipital myopathies are often mentioned but have been described in only about 10 papers. Based on a review of the literature and 10 personal cases, the term "quadricipital amyotrophic syndrome" is proposed for a group of affections which can currently be divided into: 1) primary muscular dystrophies: pure quadricipital myopathy, quadricipital myopathy "plus", lumbopelvifemoral myopathy though it is doubtful whether the latter should be included; 2) metabolic muscular disorders; 3) chronic polymyositis localized to the quadriceps; 4) spinal amyotrophy localized to the quadriceps.

In order to investigate the pathological basis of muscle hypertrophy in Duchenne dystrophy, 9 biopsy specimens of the lateral gastrocnemius and 7 of the vastus lateralis were compared. All patients had calf hypertrophy and normal strength in gastrocnemius-soleus, whereas the quadriceps biopsied were all atrophied and weak. The patients' ages ranged from 4 to 11 years. The pathological and histochemical changes were assessed semi-quantitatively. Comparison of the gastrocnemius and quadriceps groups showed that the number of hypercontracted fibres, the degree of endomysial fibrosis and the degree of fat infiltration were significantly higher in the quadriceps. The fibre type differentiation was better in the gastrocnemius group. The mean fibre diameter was above normal in all gastrocnemius biopsies and showed no increase with age. In the quadriceps, fibre hypertrophy was found early in the disease but had changed into fibre atrophy in the three oldest patients. When present, fibre hypertrophy involved both fibre types. The amount of fat-fibrosis per unit area was increased in both groups, but more severely so in the quadriceps. These results indicate that there is no true muscle hypertrophy in the gastrocnemius, in which the fat-fibrosis component was increased in all patients and that the dystrophic process is more active in the quadriceps. The finding of persistent fibre hypertrophy in the gastrocnemius is discussed with respect to the postural abnormalities observed in the lower limbs in Duchenne dystrophy.