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Manifesting carrier of X-linked Duchenne muscular dystrophy
Journal of the Neurological Sciences, 1981,49:455-463
455
© Elsevier/North-Holland Biomedical Press
MANIFESTING CARRIER OF X-LINKED D U C H E N N E MUSCULAR DYSTROPHY
GIOVANNI MEOLA, ELIO SCARPINI, VINCENZO SILANI and GUGLIELMO SCARLATO
Department of Neurology, Medical School, University of Milan, Milan (haly) (Received 7 August, 1980) (Accepted 18 September, 1980)
SUMMARY
The authors have investigated the uncommon occurrence of a boy affected with Duchenne muscular dystrophy (DMD) whose mother showed myopathic features in the clinical history, EMG, biochemical tests and muscle biopsy. This study suggests that the patient's mother is a manifesting carrier of X-linked D M D with clinical, neurophysiological, biochemical and histological findings of X-linked D M D with an almost complete inactivation of the paternal X-chromosome (lyonization).
INTRODUCTION
The original description by Duchenne (1868) of the pseudohypertrophic type of muscular dystrophy (MD) was based on 13 patients, including 2 girls. In this disease, the X-linked recessive character of inheritance is generally accepted. Families with affected females incompletely studied (Kloepfer and Talley 1958) and sporadic females (Jackson and Carey 1961) have been described. In these reports, an autosomal recessive inheritance has been invoked. On the other hand, Duchenne dystrophy has been described in females with XO genotype (Turner's syndrome) (Skeate et al. 1969), with mosaicisms XO/XX or XO/XX/XXX (Ferrier et al. 1965; Jalbert et al. 1966) or with a structurally abnormal X-chromosome (Berg and Conte 1974).
This research was supported in part by a grant from the "Dino Ferrari" Foundation, Maranello, Modena, Italy. Correspondence to: G. Meola, Department of Neurology, University of Milan, Pad. Ponti, Policlinico, Via F. Sforza 35, 20122 Milan, Italy.
456 Further, it is known that some X-linked recessive disorders can occur in females with normal karyotypes by lyonization (inactivation of the paternal Xchromosome) (Gomez et al. 1977). However, in a review of 104 reports on D M D in girls {Penn et al. 1970) there were only 19 in whom the clinical features conformed. In our study, we have investigated the uncommon occurrence of 2 patients, a manifesting carrier and her D M D affected son, studying the clinical histories, EMG, biochemical tests and muscle biopsies. CASE R E P O R T S
First patient The mother (B.E., IV-6, 34 years old) of the patient has a family history of neuromuscular disease: a maternal uncle died at the age of 20 of classic D M D , as shown in the family tree (Fig. 1). She was born at term after an uncomplicated pregnancy and delivery. Motor milestones were normal. She was quite normal until the age of 3. From that time on there were gait disturbances, frequent falling, difficulty in running and getting up stairs; until the age of 30 muscle weakness did not, however, worsen and the patient could work standing for many hours during the day. As shown in the family tree, her mating with 3 different males produced 1 boy affected with Duchenne pseudohypertrophic muscular dystrophy and 2 normal sons. At the age of 30, after the last pregnancy, she began to worsen with progressive weakness in the lower limbs. From that time on, her walking gradually deteriorated, she became unable to walk fast, tired readily, and was unable to climb stairs. On neurological examination she walked on her toes with a waddling gait. She had
1
i
2
3
e
1
2
3
4
5
6
7
8
o 9
lo
Fig. 1. Family tree. II-l, died at age 20 of "progressive muscular dystrophy": IV-6, mother of the propositus (V-5) affected by " D u c h e n n e muscular dystrophy".
457
Fig. 2. Affected mother IV-6, showing enlargement of the calves.
marked lumbar lordosis, bilateral prominence of the calves (Fig. 2) and moderate talipes equinovarus deformities. There was also weakness of the pelvic and shoulder girdles. The deep tendon reflexes were diminished. No other neurological abnormalities were found. The serum CPK was 221 mU/ml (normal values up to 50). The EMG showed a myopathic pattern. Chromosome analysis by means of both standard Giemsa and Q-band staining showed a normal karyotype.
458
Muscle biopsy A biopsy specimen was obtained from the left deltoid muscle. Cryostat sections were studied by light microscopy after histological (hematoxylin-eosin, modified Gomori trichrome) and histochemical staining (myofibrillar ATPase at pH 9.4-4.6-4.3 ; N A D H diaphorase; phosphorylase, acid phosphatase; PAS). The histological picture showed increased variability in the size of fibers, the presence of a number of large circular opaque fibers, some necrotic fibers, some of which were undergoing phagocytosis, internal nuclei, splitting and a mild degree of endomysial and perimysial fibrosis (Fig. 3). Oxidative enzyme reactions showed aspecific abnormalities of the intermyofibrillar network. On routine ATPase stain, there was type 1 fiber predominance and type 2 atrophy.
Muscle cultures The mother's muscle biopsy was grown in explant cultures according to the method of Harvey et al. (1979). Cultures were observed daily with a phase-contrast microscope. Tissue cultures grown on coverslip were stained with phosphotungstic acid-hematoxylin (PTAH) stain. The results of the muscle cultures were the following: (a) Living cultures. Migration of uninucleate cells was observed after 96 h of culture with a reduced "lag-phase" (the interval between starting the cultures and the phase of initial growth). Out-growth was composed mainly of fibroblasts and
Fig. 3. Left deltoid muscle from the mother of the patient. Marked variation in fiber size, increased number of central nuclei and splitting, some large circular opaque fibers and mild degree of endomysial fibrosis. Gomori trichrome; × 100.
459
Fig. 4. Phase contrast micrographs of cultures obtained from mother muscle biopsy at different stages of growth. A : Myoblasts typically lined up in a multicellular chain prior to cellular fusion and myotubes formation (10 days in vitro), x 100; B. Long, narrow, multinucleate myotubes with centrally placed nuclei (15 days in vitro), × 100.
some spindle-shaped mononucleate cells resembling myoblasts. Fusion of myoblasts took place after 10 days (Fig. 4A). The first multinucleate myotubes were seen after 15 days in culture and were long, narrow, and refractile, with clearly visible nuclei (Fig. 4B). No morphologic abnormalities of the cells in culture were observed by phase microscopy before or after fusion, when compared with parallel normal cultures. (b) Histology of muscle cell cultures. The cross-striations were clearly visible in myotubes 4-6 weeks old after P T A H staining. Frequently they were localized along one or the other side of the cell, and rarely extended across the full breadth of the cell (Fig. 5). Cultures were maintained for up to 8 weeks and contracting myotubes were never seen in these cultures.
460
Fig. 5. Cross-striations are clearly visible along one side of a myotube. Phosphotungstic acid- hematoxylin (6 weeks in vitro); × 1000.
Second patient The patient (V.G., V-5, 14 years old), was born following a normal pregnancy and delivery. During the first year, no abnormalities were noted, and the m o l o r milestones were attained at appropriate times. He began to walk at 18 months, but at the age of 3 he did so with a waddling gait and had difficulty in climbing stairs and running. At the age of 7, he began to walk on his toes. At the age of 9 he was unable to walk without assistance and was confined to a wheelchair; at the same age, he complained o f a proximal weakness in the upper limbs. There were skeletal deformities in the lower limbs. On neurological examination weakness of neck muscles was present; proximal muscles of the upper limbs were also extremely weak; the lower limbs were plegic. All deep reflexes were absent. Severe lumbar lordosis, bilateral hamstring contracture, and Achilles' tendon shortening with marked talipes equinovarus deformities were present. E M G showed a myopathic pattern. Serum C P K was 30 m U / m l (normal values up to 50). The low C P K level reflects the pathological picture of muscle biopsy.
Muscle biopsy The biopsy specimen, obtained from the left deltoid muscle, was largely replaced by adipose tissue with residual islets of muscle fibers (no more than 8-9 fibers), some of which were hypertrophic and opaque, with some central nuclei (Fig. 6).
461
Fig. 6. Leftdeltoid muscle from the propositus. Isolated clusters of residual muscle fibers and extensive adipose tissue replacement.Gomori trichrome; x 25. It was not possible to set up muscle Cultures from the patient because his muscle biopsy specimen contained only a few fibers, largely replaced by adipose tissue. DISCUSSION The mother of the DMD-affected patient showed myopathic features according to her clinical history, EMG, biochemical tests and muscle biopsy. X-linked recessive disorders can occur in females by inactivation of the paternal X-chromosome (lyonization). In most cases this process does not affect all the cells: some pathological characters may manifest themselves in "carriers" such as elevated CPK, EMG, and histological abnormalities, but severe clinical symptoms and signs are uncommon (Zatz et al. 1973). In our case this hypothesis seems reasonable, although the interpretation is complicated by 2 female carriers (II-2, III-3), who do not manifest pathological characteristics. In our female, the disease appeared in childhood and is now evident not only clinically, but also from laboratory investigations: the histological findings show a typical myopathic pattern. The occurrence of symptoms and signs of myopathy excludes a diagnosis of D M D with autosomal recessive inheritance: in s~lach a case the genetic abnormalities would not manifest phenotypically in the mother of the propositus. The normal karyotype might also rule out Turner's syndrome and any structural alteration recognizable with Q-banding. The cultures of the mother's muscle showed a short lag-phase, in agreement with Kakulas et al. (1968), but this period is always within normal range according
462 to Dubowitz (1973). The morphologic appearance of cultured cells was normal as other studies have shown (Bishop et al. 1971; Gallup et al. 1972; Dubowitz 1973~ Askanas and Engel 1975; Ionasescu et al. 1976, 1979; Mawatari et al. 1976: Witkowski 1977). This study suggests that the patient's mother is a manifesting DMD carrier with clinical, neurophysiological, biochemical and histological findings of X-linked DMD. ACKNOWLEDGEMENTS
The authors wish to thank Prof. L. De Carli (Istituto di Genetica, University of Pavia) for his helpful criticism and Miss F. Rossella (Istituto di Biologia Generale, University of Milan) for the excellent technical assistance in performing chromosome analysis. REFERENCES Askanas, V. and W.K. Engel (1975) A new program for investigating adult human skeletal muscle grown aneurally in tissue culture, Neurology (Minneap.), 25 : 58-67. Berg, B. O. and F. Conte (1974) Duchenne muscular dystrophy in a female with a structurally abnormal X-chromosome, Neurology (Minneap.), 24: 356. Bishop, A., B. Gallup, Y. Skeate and V. Dubowitz (1971) Morphological studies on normal and diseased human muscle in culture, J. neurol. Sci., 13:333 350. Caspersson, T., G. Lomakka and L. Zech (1971) 24 fluorescence patterns of human chromosome Distinguishing characters and variability, Hereditas, 67: 89-102. Dubowitz, V. (1973) Some observations on normal and diseased human muscle in tissue culture. In: C. M. Pearson and F. K. Mostofi (Eds.), The StriatedMusele, Williams and Wilkins, Baltimore, MD, 1973, pp. 473-484. Duchenne, G.B. (1868) Recherches sur la paralysie musculaire pseudohypertrophique ou paralysie myo-scl6rosique, Arch. g~n. todd. (6. Ser.), 1t: 5-25, 179-209, 305-321,421-443, 552-588, 868. Ferrier, P., F. Bamatter and D. Klein (1965) Muscular dystrophy (Duchenne) in a girl with Turner's syndrome, J. Mkd. gknet., 2 : 38-46. Gallup, B., A. Bishop and V. Dubowitz (1972) Autoradiographic studies of RNA and DNA synthesis during myogenesis in cultures of human chick and rat muscle, J. neurol. Sei., 17:127 140. Gomez, M. R., A.G. Engel, G. Dewald and H. A. Peterson (1977) Failure of inactivation of Duchenne dystrophy X-chromosome in one of female identical twins, Neurology (Minneap.), 27: 537-541. Harvey, A. L., J. G. Robertson and A. J. Witkowski (1979) Maturation of human skeletal muscle fibres in explant tissue culture, J. neurol. Sci., 41 : 115-122. lonasescu, V., M. Zellweger, R. Ionasescu, G. Lara-Braud and P.A. Cancilla (1976) Protein synthesis in muscle cultures from patients with Duchenne muscular dystrophy, Acta neurol. Stand., 54: 241-247. Ionasescu, V., L.Z. Stern, R. Ionasescu and P. Rubenstein (1979) Stimulatory effects of drugs for protein synthesis on muscle cultures in Duchenne dystrophy, Ann. Neurol., 5:t07-110. Jackson, C.E. and J.H. Carey (1961) Progressive muscular dystrophy - - Autosomal recessive type, Pediatrics, 28: 77-84. Jalbert, P., D. Mouriquand and A. Beaudoing (1966) Myopathie progressive de type Duchenne el mosaique XO/XX/XXX - - Consid6rations sur la g6n~se de la fibre muscutaire stri~e, Ann. g~net. (Paris), 96: 104108. Kakulas, B.A., J.M. Papadimitriou, J.D. Knight and F.L. Mastaglia (1968) Normal and abnormal human muscle in tissue culture, Proc. Aust. Ass. Neurol., 12: 79-85. Kloepfer, H.W. and C. Talley (1958) Autosomal recessive inheritance of Duchenne-type muscular dystrophy, Ann. hum. Genet., 22:138-143.
463 Mawatari. S., A. Miranda and L. P. Rowland (1976) Adenyl-cyclase abnormality in Duchenne muscular dystrophy - - Muscle cells in culture, Neurology (Minneap.), 26: 1021-1026. Penn, A.S., R.P. Lisak and L.P. Rowland (1970) Muscular dystrophy in young girls, Neurology (Minneap.), 20: 147-159. Skeate, Y., A. Bishop and V. Dubowitz (1969) Differentiation of diseased h u m a n muscle in culture, Cell and Tissue Kin., 2 : 307 310. Walton, J. N. (1956) The inheritance of muscular dystrophy - - Further observations, Ann. hum. Genet., 21 : 40-58. Witkowski, J. A. (1977) Diseased muscle cells in culture, Biol. Rev., 52:431-476. Zatz. M., R.B. Levisky, J.A. Levy, B.O. Valente, M. Gianotti and O. Frota-Pessoa (1973) Clinical symptoms in a female carrier of a Duchenne muscular dystrophy, J. G~net. hum., 21 : 297 305.
455
© Elsevier/North-Holland Biomedical Press
MANIFESTING CARRIER OF X-LINKED D U C H E N N E MUSCULAR DYSTROPHY
GIOVANNI MEOLA, ELIO SCARPINI, VINCENZO SILANI and GUGLIELMO SCARLATO
Department of Neurology, Medical School, University of Milan, Milan (haly) (Received 7 August, 1980) (Accepted 18 September, 1980)
SUMMARY
The authors have investigated the uncommon occurrence of a boy affected with Duchenne muscular dystrophy (DMD) whose mother showed myopathic features in the clinical history, EMG, biochemical tests and muscle biopsy. This study suggests that the patient's mother is a manifesting carrier of X-linked D M D with clinical, neurophysiological, biochemical and histological findings of X-linked D M D with an almost complete inactivation of the paternal X-chromosome (lyonization).
INTRODUCTION
The original description by Duchenne (1868) of the pseudohypertrophic type of muscular dystrophy (MD) was based on 13 patients, including 2 girls. In this disease, the X-linked recessive character of inheritance is generally accepted. Families with affected females incompletely studied (Kloepfer and Talley 1958) and sporadic females (Jackson and Carey 1961) have been described. In these reports, an autosomal recessive inheritance has been invoked. On the other hand, Duchenne dystrophy has been described in females with XO genotype (Turner's syndrome) (Skeate et al. 1969), with mosaicisms XO/XX or XO/XX/XXX (Ferrier et al. 1965; Jalbert et al. 1966) or with a structurally abnormal X-chromosome (Berg and Conte 1974).
This research was supported in part by a grant from the "Dino Ferrari" Foundation, Maranello, Modena, Italy. Correspondence to: G. Meola, Department of Neurology, University of Milan, Pad. Ponti, Policlinico, Via F. Sforza 35, 20122 Milan, Italy.
456 Further, it is known that some X-linked recessive disorders can occur in females with normal karyotypes by lyonization (inactivation of the paternal Xchromosome) (Gomez et al. 1977). However, in a review of 104 reports on D M D in girls {Penn et al. 1970) there were only 19 in whom the clinical features conformed. In our study, we have investigated the uncommon occurrence of 2 patients, a manifesting carrier and her D M D affected son, studying the clinical histories, EMG, biochemical tests and muscle biopsies. CASE R E P O R T S
First patient The mother (B.E., IV-6, 34 years old) of the patient has a family history of neuromuscular disease: a maternal uncle died at the age of 20 of classic D M D , as shown in the family tree (Fig. 1). She was born at term after an uncomplicated pregnancy and delivery. Motor milestones were normal. She was quite normal until the age of 3. From that time on there were gait disturbances, frequent falling, difficulty in running and getting up stairs; until the age of 30 muscle weakness did not, however, worsen and the patient could work standing for many hours during the day. As shown in the family tree, her mating with 3 different males produced 1 boy affected with Duchenne pseudohypertrophic muscular dystrophy and 2 normal sons. At the age of 30, after the last pregnancy, she began to worsen with progressive weakness in the lower limbs. From that time on, her walking gradually deteriorated, she became unable to walk fast, tired readily, and was unable to climb stairs. On neurological examination she walked on her toes with a waddling gait. She had
1
i
2
3
e
1
2
3
4
5
6
7
8
o 9
lo
Fig. 1. Family tree. II-l, died at age 20 of "progressive muscular dystrophy": IV-6, mother of the propositus (V-5) affected by " D u c h e n n e muscular dystrophy".
457
Fig. 2. Affected mother IV-6, showing enlargement of the calves.
marked lumbar lordosis, bilateral prominence of the calves (Fig. 2) and moderate talipes equinovarus deformities. There was also weakness of the pelvic and shoulder girdles. The deep tendon reflexes were diminished. No other neurological abnormalities were found. The serum CPK was 221 mU/ml (normal values up to 50). The EMG showed a myopathic pattern. Chromosome analysis by means of both standard Giemsa and Q-band staining showed a normal karyotype.
458
Muscle biopsy A biopsy specimen was obtained from the left deltoid muscle. Cryostat sections were studied by light microscopy after histological (hematoxylin-eosin, modified Gomori trichrome) and histochemical staining (myofibrillar ATPase at pH 9.4-4.6-4.3 ; N A D H diaphorase; phosphorylase, acid phosphatase; PAS). The histological picture showed increased variability in the size of fibers, the presence of a number of large circular opaque fibers, some necrotic fibers, some of which were undergoing phagocytosis, internal nuclei, splitting and a mild degree of endomysial and perimysial fibrosis (Fig. 3). Oxidative enzyme reactions showed aspecific abnormalities of the intermyofibrillar network. On routine ATPase stain, there was type 1 fiber predominance and type 2 atrophy.
Muscle cultures The mother's muscle biopsy was grown in explant cultures according to the method of Harvey et al. (1979). Cultures were observed daily with a phase-contrast microscope. Tissue cultures grown on coverslip were stained with phosphotungstic acid-hematoxylin (PTAH) stain. The results of the muscle cultures were the following: (a) Living cultures. Migration of uninucleate cells was observed after 96 h of culture with a reduced "lag-phase" (the interval between starting the cultures and the phase of initial growth). Out-growth was composed mainly of fibroblasts and
Fig. 3. Left deltoid muscle from the mother of the patient. Marked variation in fiber size, increased number of central nuclei and splitting, some large circular opaque fibers and mild degree of endomysial fibrosis. Gomori trichrome; × 100.
459
Fig. 4. Phase contrast micrographs of cultures obtained from mother muscle biopsy at different stages of growth. A : Myoblasts typically lined up in a multicellular chain prior to cellular fusion and myotubes formation (10 days in vitro), x 100; B. Long, narrow, multinucleate myotubes with centrally placed nuclei (15 days in vitro), × 100.
some spindle-shaped mononucleate cells resembling myoblasts. Fusion of myoblasts took place after 10 days (Fig. 4A). The first multinucleate myotubes were seen after 15 days in culture and were long, narrow, and refractile, with clearly visible nuclei (Fig. 4B). No morphologic abnormalities of the cells in culture were observed by phase microscopy before or after fusion, when compared with parallel normal cultures. (b) Histology of muscle cell cultures. The cross-striations were clearly visible in myotubes 4-6 weeks old after P T A H staining. Frequently they were localized along one or the other side of the cell, and rarely extended across the full breadth of the cell (Fig. 5). Cultures were maintained for up to 8 weeks and contracting myotubes were never seen in these cultures.
460
Fig. 5. Cross-striations are clearly visible along one side of a myotube. Phosphotungstic acid- hematoxylin (6 weeks in vitro); × 1000.
Second patient The patient (V.G., V-5, 14 years old), was born following a normal pregnancy and delivery. During the first year, no abnormalities were noted, and the m o l o r milestones were attained at appropriate times. He began to walk at 18 months, but at the age of 3 he did so with a waddling gait and had difficulty in climbing stairs and running. At the age of 7, he began to walk on his toes. At the age of 9 he was unable to walk without assistance and was confined to a wheelchair; at the same age, he complained o f a proximal weakness in the upper limbs. There were skeletal deformities in the lower limbs. On neurological examination weakness of neck muscles was present; proximal muscles of the upper limbs were also extremely weak; the lower limbs were plegic. All deep reflexes were absent. Severe lumbar lordosis, bilateral hamstring contracture, and Achilles' tendon shortening with marked talipes equinovarus deformities were present. E M G showed a myopathic pattern. Serum C P K was 30 m U / m l (normal values up to 50). The low C P K level reflects the pathological picture of muscle biopsy.
Muscle biopsy The biopsy specimen, obtained from the left deltoid muscle, was largely replaced by adipose tissue with residual islets of muscle fibers (no more than 8-9 fibers), some of which were hypertrophic and opaque, with some central nuclei (Fig. 6).
461
Fig. 6. Leftdeltoid muscle from the propositus. Isolated clusters of residual muscle fibers and extensive adipose tissue replacement.Gomori trichrome; x 25. It was not possible to set up muscle Cultures from the patient because his muscle biopsy specimen contained only a few fibers, largely replaced by adipose tissue. DISCUSSION The mother of the DMD-affected patient showed myopathic features according to her clinical history, EMG, biochemical tests and muscle biopsy. X-linked recessive disorders can occur in females by inactivation of the paternal X-chromosome (lyonization). In most cases this process does not affect all the cells: some pathological characters may manifest themselves in "carriers" such as elevated CPK, EMG, and histological abnormalities, but severe clinical symptoms and signs are uncommon (Zatz et al. 1973). In our case this hypothesis seems reasonable, although the interpretation is complicated by 2 female carriers (II-2, III-3), who do not manifest pathological characteristics. In our female, the disease appeared in childhood and is now evident not only clinically, but also from laboratory investigations: the histological findings show a typical myopathic pattern. The occurrence of symptoms and signs of myopathy excludes a diagnosis of D M D with autosomal recessive inheritance: in s~lach a case the genetic abnormalities would not manifest phenotypically in the mother of the propositus. The normal karyotype might also rule out Turner's syndrome and any structural alteration recognizable with Q-banding. The cultures of the mother's muscle showed a short lag-phase, in agreement with Kakulas et al. (1968), but this period is always within normal range according
462 to Dubowitz (1973). The morphologic appearance of cultured cells was normal as other studies have shown (Bishop et al. 1971; Gallup et al. 1972; Dubowitz 1973~ Askanas and Engel 1975; Ionasescu et al. 1976, 1979; Mawatari et al. 1976: Witkowski 1977). This study suggests that the patient's mother is a manifesting DMD carrier with clinical, neurophysiological, biochemical and histological findings of X-linked DMD. ACKNOWLEDGEMENTS
The authors wish to thank Prof. L. De Carli (Istituto di Genetica, University of Pavia) for his helpful criticism and Miss F. Rossella (Istituto di Biologia Generale, University of Milan) for the excellent technical assistance in performing chromosome analysis. REFERENCES Askanas, V. and W.K. Engel (1975) A new program for investigating adult human skeletal muscle grown aneurally in tissue culture, Neurology (Minneap.), 25 : 58-67. Berg, B. O. and F. Conte (1974) Duchenne muscular dystrophy in a female with a structurally abnormal X-chromosome, Neurology (Minneap.), 24: 356. Bishop, A., B. Gallup, Y. Skeate and V. Dubowitz (1971) Morphological studies on normal and diseased human muscle in culture, J. neurol. Sci., 13:333 350. Caspersson, T., G. Lomakka and L. Zech (1971) 24 fluorescence patterns of human chromosome Distinguishing characters and variability, Hereditas, 67: 89-102. Dubowitz, V. (1973) Some observations on normal and diseased human muscle in tissue culture. In: C. M. Pearson and F. K. Mostofi (Eds.), The StriatedMusele, Williams and Wilkins, Baltimore, MD, 1973, pp. 473-484. Duchenne, G.B. (1868) Recherches sur la paralysie musculaire pseudohypertrophique ou paralysie myo-scl6rosique, Arch. g~n. todd. (6. Ser.), 1t: 5-25, 179-209, 305-321,421-443, 552-588, 868. Ferrier, P., F. Bamatter and D. Klein (1965) Muscular dystrophy (Duchenne) in a girl with Turner's syndrome, J. Mkd. gknet., 2 : 38-46. Gallup, B., A. Bishop and V. Dubowitz (1972) Autoradiographic studies of RNA and DNA synthesis during myogenesis in cultures of human chick and rat muscle, J. neurol. Sei., 17:127 140. Gomez, M. R., A.G. Engel, G. Dewald and H. A. Peterson (1977) Failure of inactivation of Duchenne dystrophy X-chromosome in one of female identical twins, Neurology (Minneap.), 27: 537-541. Harvey, A. L., J. G. Robertson and A. J. Witkowski (1979) Maturation of human skeletal muscle fibres in explant tissue culture, J. neurol. Sci., 41 : 115-122. lonasescu, V., M. Zellweger, R. Ionasescu, G. Lara-Braud and P.A. Cancilla (1976) Protein synthesis in muscle cultures from patients with Duchenne muscular dystrophy, Acta neurol. Stand., 54: 241-247. Ionasescu, V., L.Z. Stern, R. Ionasescu and P. Rubenstein (1979) Stimulatory effects of drugs for protein synthesis on muscle cultures in Duchenne dystrophy, Ann. Neurol., 5:t07-110. Jackson, C.E. and J.H. Carey (1961) Progressive muscular dystrophy - - Autosomal recessive type, Pediatrics, 28: 77-84. Jalbert, P., D. Mouriquand and A. Beaudoing (1966) Myopathie progressive de type Duchenne el mosaique XO/XX/XXX - - Consid6rations sur la g6n~se de la fibre muscutaire stri~e, Ann. g~net. (Paris), 96: 104108. Kakulas, B.A., J.M. Papadimitriou, J.D. Knight and F.L. Mastaglia (1968) Normal and abnormal human muscle in tissue culture, Proc. Aust. Ass. Neurol., 12: 79-85. Kloepfer, H.W. and C. Talley (1958) Autosomal recessive inheritance of Duchenne-type muscular dystrophy, Ann. hum. Genet., 22:138-143.
463 Mawatari. S., A. Miranda and L. P. Rowland (1976) Adenyl-cyclase abnormality in Duchenne muscular dystrophy - - Muscle cells in culture, Neurology (Minneap.), 26: 1021-1026. Penn, A.S., R.P. Lisak and L.P. Rowland (1970) Muscular dystrophy in young girls, Neurology (Minneap.), 20: 147-159. Skeate, Y., A. Bishop and V. Dubowitz (1969) Differentiation of diseased h u m a n muscle in culture, Cell and Tissue Kin., 2 : 307 310. Walton, J. N. (1956) The inheritance of muscular dystrophy - - Further observations, Ann. hum. Genet., 21 : 40-58. Witkowski, J. A. (1977) Diseased muscle cells in culture, Biol. Rev., 52:431-476. Zatz. M., R.B. Levisky, J.A. Levy, B.O. Valente, M. Gianotti and O. Frota-Pessoa (1973) Clinical symptoms in a female carrier of a Duchenne muscular dystrophy, J. G~net. hum., 21 : 297 305.