A genetic study of the Fukuyama type congenital muscular dystrophy

A genetic study was carried out on 153 families with 186 Fukuyama type congenital progressive muscular dystrophy (FCMD) patients. Consanguineous marriage of parents was found in 41 families (26.80%). Inbreeding coefficients in the patients was 10 times as high as that of the general population. Both sexes were almost equally affected (M:F = 1.1:1.0). No single parent of the patients was affected. Recurrence among siblings was frequent (9 out of 41 siblings in offspring of related parents and 18 out of 110 siblings in offspring of unrelated parents were affected. The segregation ratio was 23.91-27.08% in offspring of related parents, 20.00-22.94% in offspring of unrelated parents, these values being not significantly different from the 25% expected from the assumption of autosomal recessive mode of inheritance. In the sample two twin pairs were included, of which one male isosexual pair was concordant. Sporadic cases were not significantly more numerous than expected. All these data indicate that the disorder is caused by homozygosity of an autosomal recessive gene. Frequency of the gene was estimated to be 5.2-9.7 X 10(-3) and frequency of the patients 6.9-11.9 X 10(-5). Mutation rate was estimated to be 6.9-11.9 X 10(-5).     

Fukuyama type congenital muscular dystrophy--two Dutch siblings

Two Dutch siblings, diagnosed as suffering from Fukuyama type congenital muscular dystrophy (FCMD) on the basis of clinical, computerized tomography (CT), and muscle and brain biopsy findings, are reported. Hypoplasia of the chorioidea was observed for the first time in FCMD. Autopsy of the first case revealed the major pathological changes of FCMD, i.e. micropolygyria, loss of cytoarchitecture, hypoplasia of the pyramidal tract, leptomeningeal thickening. Heterotopias of nervous tissue in the spinal arachnoidal spaces were found. This is the first case in which brain tissue has been investigated on two separate occasions. In the biopsy specimen--at the age of 14 months--myelination was poor and astrogliosis marked. At autopsy--4 years later--myelination proved to be only slightly less than normal. However, white matter hypodensities on the successive CT's did not change. There is no ready explanation for this discrepancy. Typical FCMD is compared to FCMD-like cases from outside Japan. There are arguments in favor of the concept of a continuum of diseases--with the same (unknown) etiology--representing both typical FCMD and other types of congenital muscular dystrophy with CNS lesions.     

Ullrich's congenital atonic sclerotic muscular dystrophy

Summary A 5-year old girl with Ullrich's atonic-sclerotic muscular dystrophy is reported and 16 previously reported cases are reviewed. The clinical features, in particular proximal contractures, distal hyperextensibility, mild dysmorphism and hyperhidrosis, allow recognition of this subtype of congenital muscular dystrophy, which has no specific pathological characteristics. There is evidence in favour of an autosomal recessive mode of inheritance.     

Epilepsy in patients with advanced Fukuyama congenital muscular dystrophy

BackgroundRecent advances in respiratory management have improved survival for patients with Fukuyama congenital muscular dystrophy (FCMD), characterized by congenital muscular dystrophy and brain malformation. Previous studies reported that more than half of patients exhibit seizures in childhood. However, little is known about epilepsy after childhood.MethodsTo elucidate the long-term clinical course of epilepsy, we retrospectively reviewed all medical records in nine patients (6 males, mean age 20.7 years) with FCMD diagnosed between 1981 and 2019.ResultsThe follow-up periods ranged from 6 to 30 years (mean 18.4 years). A total of 75 EEG recordings were available from nine patients. In some patients, EEGs were normal during early childhood but tended to show paroxysmal discharges with age. Overall, epileptic seizures were observed in six patients. Except for one presenting with afebrile seizure at one year of age, the remaining five patients developed epilepsy between 13 and 22 years of age. The most common seizure type was focal impaired awareness seizure. After adolescence, four patients exhibited status epilepticus. Their convulsive movements of the seizures became less prominent with progression of the disease. At the last evaluation, most patients (5/6) had uncontrolled seizures.ConclusionsDespite presence of distinct brain malformation, epileptic seizures may develop after childhood in FCMD patients. Our experience suggests that clinicians should be careful not to overlook epileptic seizures, especially in advanced-stage patients who had profound muscle weakness.     

Fukuyama type congenital muscular dystrophy as a natural model of childhood epilepsy.

Fukuyama type Congenital Muscular Dystrophy, inherited autosomal-recessively, is characterized by muscular dystrophy associated with severe mental retardation and epileptic convulsions. By examining 56 cases, followed for more than three years, 75 EEG records from 40 patients and visual evoked potentials from 11 patients with reference to autopsied materials, the authors aimed at clarifying the causative relationship between congenital central nervous system (CNS) lesions and childhood epilepsy. In 36 out of 56 cases diffuse epileptic seizures were observed with onset at 1.64 +/- 1.01 years average. In 32/36 cases seizures developed before 3 years of age. In 51/75 EEGs focal paroxysmal discharges (FPD), fronto-contro-parietal in younger and centro-occipital in older cases, were observed. Abnormal basic activities (ABA), diffuse-alpha-activity and/or abundant or extreme spindles, were observed more often in older than younger cases. The incidence of FPD was similar between convulsive and non-convulsive cases, but ABA predominated in the former, VEP revealed abnormal findings in 64% of 11 cases examined. Of the CNS pathology, consisting of cerebral and cerebellar gyral abnormalities and a hypoplastic corticospinal tract, the gyral lesions (verrucous polymicrogyria with adhesions of adjacent gyri and cellular disarrangement) were thought to be lesions causing epilepsy. Cortical nonprogressive gyral lesions occurring around the second trimester could cause FPD and clinical diffuse epileptic seizures develop with other factors concerned with ABA.     

Cardiac involvement in Fukuyama muscular dystrophy is less severe than in Duchenne muscular dystrophy

Background

One of the main complications in patients with muscular dystrophies is cardiac dysfunction. The literature on cardiac involvement in patients with Fukuyama congenital muscular dystrophy (FCMD) is limited.

Renal dysfunction is rare in Fukuyama congenital muscular dystrophy

Background

The leading cause of death in patients with Fukuyama congenital muscular dystrophy (FCMD) is congestive heart failure or respiratory dysfunction, which is same as that in Duchenne muscular dystrophy (DMD). Recent studies reported that renal dysfunction is a common complication and an increasing cause of death in advanced DMD. It can be attributable to circulatory instability or inappropriate use of drugs for treating cardiac dysfunction.

FKRP mutations cause congenital muscular dystrophy 1C and limb-girdle muscular dystrophy 2I in Asian patients

Mutation in the fukutin-related protein (FKRP) gene causes alpha-dystroglycanopathies, a group of autosomal recessive disorders associated with defective glycosylated alpha-dystroglycan (α-DG). The disease phenotype shows a broad spectrum, from the most severe congenital form involving brain and eye anomalies to milder limb-girdle form. FKRP-related alpha-dystroglycanopathies are common in European countries. However, a limited number of patients have been reported in Asian countries. Here, we presented the clinical, pathological, and genetic findings of nine patients with FKRP mutations identified at a single muscle repository center in Japan. Three and six patients were diagnosed with congenital muscular dystrophy type 1C and limb-girdle muscular dystrophy 2I, respectively. None of our Asian patients showed the most severe form of alpha-dystroglycanopathy. While all patients showed a reduction in glycosylated α-DG levels, to variable degrees, these levels did not correlate to clinical severity. Fifteen distinct pathogenic mutations were identified in our cohort, including five novel mutations. Unlike in the populations belonging to European countries, no common mutation was found in our cohort.     

Fukuyama congenital muscular dystrophy: Cortical dysplasia of the cerebrum in a 20 week fetus

This report describes cerebral cortical dysplasia in a 20 week fetus, aborted as a result of the prenatal genetic analysis which provided evidence of Fukuyama congenital muscular dystrophy (FCMD). The histological appearance of the brain of this fetus was similar to that of previously described cases. However, cortical dysplasia was less severe in this 20 week fetus, and the interesting finding was the existence of a leptomeningeal lesion probably preceding dysplasia. In this case, abnormal findings were found mainly in the cerebral surface, and maturation of the brain seemed appropriate for the gestational age. Furthermore, periodic acid-methenamine-silver-positive linear structure of the cerebral surface was disrupted irregularly. These findings suggest that defects in the pial-glial barrier of the cerebral surface may play a cardinal role for the genesis of cortical dysplasia. It is suggested that the extracortical abnormal tissue would be detectable morphologically at least in the 12-13th week because cells considered as subpial granular cells were contained in the lesion. This report on the brain of a fetus with FCMD provides information on relatively early central nervous system alterations in this disease, and may be of importance in clarifying their pathogenesis.     

Erythrocyte flexibility, ATPase activities and Ca efflux in patients with Duchenne muscular dystrophy, myotonic muscular dystrophy and congenital myotonia

Erythrocyte flexibility measured by a polycarbonate membrane filtration method showed increased fragility (265 +/- 163 Hb mg/l vs. controls 86 +/- 72 Hb mg/l; mean +/- SD; P less than 0.0025) and increased rigidity (123 +/- 96 mm Hg vs. 79 +/- 19 mm Hg; P less than 0.05) in patients with congenital myotonia, while both parameters were normal in patients with Duchenne muscular dystrophy or with myotonic dystrophy. Erythrocyte ghosts obtained from patients with MyD displayed highly significant increases in both (Na+ + K+)-ATPase and (Ca2+ + Mg2+)-ATPase activities (P less than 0.005) and to a lesser extent in Mg2+-ATPase activity (P less than 0.05), while no difference was seen between patients with DMD and age-matched controls. The efflux of Ca2+ was increased from erythrocytes of patients with DMD as compared to age-matched controls (82 +/- 2% vs. 70 +/- 4%; P less than 0.005), while no difference was detected between patients with MyD and age-matched controls.     

Altered glycosylation of alpha-dystroglycan in neurons of Fukuyama congenital muscular dystrophy brains

To test the hypothesis that the disruption of fukutin protein produces the brain pathology through hypoglycosylation of alpha-dystroglycan (alpha-DG), we immunostained Fukuyama congenital muscular dystrophy (FCMD) brains with an antibody that recognizes the polysaccharide epitope of alpha-DG. Immunoreactivity of the glia-limitans along the cortical surface, as well as that of the glial endfeet around vessel walls, was preserved in the FCMD cerebrum. However, fragmentation of the immunostained glia-limitans was noted in association with parenchymal protrusion and gyral fusion. In the FCMD cerebellum, this fragmentation of alpha-DG labeling was limited to the area of micropolygyria, and immunostaining at the glia-limitans and vessel walls was comparable to that of the control brains, in structurally normal areas. In the hippocampus, neurons of the dentate gyrus and corpus ammonis were immunopositive for alpha-DG in control subjects, but this staining was markedly decreased in FCMD brains. In contrast, immunolabeling of blood vessels and the glia-limitans was preserved in this region. Fukutin antisera clearly labeled hippocampal neurons in control brains, while this labeling was decreased in FCMD brains. Thus, hypoglycosylation of alpha-DG was evident in neurons, but not in the glial cell population of FCMD brains. This suggests that the mechanism of alpha-DG glycosylation may differ between neurons and glial cells, and that a fukutin gene defect may result in functional disruption through hypoglycosylation of both neuronal and glial alpha-DG.     

Basement membrane abnormality in merosin-negative congenital muscular dystrophy

In muscle biopsy specimens from three patients with merosin-negative congenital muscular dystrophy (CMD), there was marked variation in fiber size with evidence of necrotic and regenerating processes and with marked interstitial fibrosis. No muscle fibers or intramuscular nerves stained with merosin antibody. On electron microscopy, the basement membrane of all the muscle fibers was very poorly discernible and there were occasional disruptions, while the basement membrane of the Schwann cells was well preserved. On the other hand, the sarcolemmal basement membrane in merosin-positive CMD was well preserved even in a patient with severe interstitial fibrosis. It remains to be determined how the defective basement membrane in merosin-negative CMD induces defective sarcolemma and eventual fiber necrosis. Received: 9 June 1995 / Revised, accepted: 23 October 1995     

Small size of orthogonal array in muscle plasma membrane of Fukuyama type congenital muscular dystrophy

Summary Freeze fracture analysis was carried out on the density of orthogonal array subunit particles in the plasma membrane of skeletal muscle of six patients with Fukuyama type congenital muscular dystrophy and seven control cases. The group mean density of orthogonal array subunit particles per one orthogonal array was significantly lower in the plasma membrane of Fukuyama patients. The results suggested the possible impairment of orthogonal array function in the plasma membrane of muscle fibers in congenital muscular dystrophy of the Fukuyama type.Supported in part by grant from the National Center for Nervous, Mental and Muscular Disorders of the Ministry of Health and Welfare (No. 85-04-34), Japan     

Lissencephaly with congenital muscular dystrophy and ocular abnormalities: cerebro-oculo-muscular syndrome

A Japanese male infant with lissencephaly, congenital muscular dystrophy (CMD), and ocular abnormalities is described. This patient represents features of the cerebro-oculo-muscular syndrome. Cranial computerized tomography revealed diffuse agyria, low density of the white matter, and hypoplasia of the cerebellar vermis. Brain histology suggested type II lissencephaly. These findings are correlated with other similar conditions, such as Walker-Warburg syndrome, Fukuyama-type CMD, and muscle, eye and brain disease.     

The gross motor function measure is valid for Fukuyama congenital muscular dystrophy

Fukuyama congenital muscular dystrophy (FCMD) is the second most common muscular dystrophy in Japan. FCMD is an autosomal recessive disorder caused by mutations in the fukutin gene. The main features of FCMD are a combination of infantile-onset hypotonia, generalized muscle weakness, eye abnormalities, and mental retardation associated with cortical migration defects, and most patients are never able to walk. To date, the development of a quantitative motor scale for FMCD has been difficult due to the moderate-to-severe intellectual impairment that accompanies FCMD. Gross motor function measure (GMFM), originally developed as a quantitative motor scale for cerebral palsy, can precisely and quantitatively assess motor function without complicated instructions, and was recently reported to be useful in the assessment of Down syndrome and spinal muscular atrophy. To confirm the validity of GMFM for the assessment of FCMD, 41 FCMD patients (age range: 0.6–24.4 years) were recruited for this study. The GMFM scores correlated significantly with those of two previously used motor scales, and the time-dependent change in GMFM scores was consistent with the natural course of FCMD. The inter-rater reliability, based on determinations made by four physiotherapists blinded to each other's assessment results, was excellent. We concluded GMFM to be a useful and valid measure of motor function in FCMD patients.     

Infection-associated decrease of serum creatine kinase levels in Fukuyama congenital muscular dystrophy

BackgroundMarked decreases in serum creatine kinase levels have been noted in Duchenne and Becker muscular dystrophies as rare complications of autoimmune or autoinflammatory diseases.Subjects and methodsThe influence of systemic inflammation on serum creatine kinase levels was reviewed from the charts of three subjects with Fukuyama congenital muscular dystrophy.ResultsA total of 30 infectious events were identified. Elevated serum C-reactive protein levels coincided with decreased creatine kinase levels on 19 occasions. In one subject, administration of 2 mg/kg/d prednisolone for bronchial asthma resulted in a decrease in creatine kinase level on six other occasions.ConclusionApart from an increase in endogenous cortisol secretion, certain inflammation-related molecules could play a role in mitigating muscle cell damage in Fukuyama congenital muscular dystrophy during febrile infectious episodes. Corticosteroids may be a promising agent for the treatment of muscular symptoms in this disorder.     

A short form of gross motor function measure for Fukuyama congenital muscular dystrophy

ObjectivesThe objective of this study was to confirm the validity of a short form of gross motor function measure for Fukuyama congenital muscular dystrophy (GMFM for FCMD).MethodsThis study is a case series and was conducted at the Tokyo Women’s Medical University. Fifteen patients with FCMD were assessed using both the GMFM for FCMD with 68 items, which was created as a motor function measure for patients with FCMD on the basis of Rasch analysis, and the original GMFM with 88 items. The correlation between the GMFM for FCMD and the Ueda classification was assessed. Time required for each assessment was also evaluated.ResultsWe found significant correlation between the GMFM for FCMD and the Ueda classification (r = 0.935); furthermore, the mean assessment time tended to decrease when using the GMFM for FCMD.ConclusionsGMFM for FCMD may be an appropriate motor function scale for patients with FCMD and might help decrease the assessment time.     

Benign congenital muscular dystrophy with autosomal dominant heredity: problems of classification

Summary A family with autosomal dominant congenital muscular dystrophy affecting members of both sexes in three generations is described; a father and his two sons were studied. The onset of symptoms was in early childhood and progression, if any, was slow. The proximal limb muscles, the sternocleidomastoid and anterior tibial muscles were affected. One patient had torticollis and all had heel-cord shortening. An electrophysiological examination showed myopathy. There was no cardiomyopathy. Creatine kinase (CK) was elevated, and a histological study revealed a necrotizing myopathy with pronounced regeneration and formation of aberrant myofibrils (ringbinden) and fibrosis.