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Genetic Pattern of 3 Cases of Emery–Dreifuss Muscular Dystrophy in a Family P Eastern Mediterranean Health Journal, Vol. 13, No. 1, 2007 201 Case report Genetic pattern of 3 cases of Emery–Dreifuss muscular dystrophy in a family P. Yazdanpanah,1 A. Javan,2 B. Nadimi3 and H.R. Ghaffarian Shirazi 4 Introduction and a prolonged PR interval on the electrocc cardiogram (ECG) [2]. Arrhythmias are the The muscular dystrophies are inherited primary manifestation of cardiac disease in conditions characterized by progressive EDMD [4]. myopathy [1]. The most common types are ECGs are generally abnormal by age Duchenne muscular dystrophy and Becker 20–30 years, commonly showing firstcdec muscular dystrophy. Emery–Dreifuss muscc gree atrioventricular block. The atria appear cular dystrophy (EDMD), the type reported to be involved earlier than the ventricles, here, is less common. Worldwide incidence with atrial fibrillation and atrial flutter or, is estimated to be 1 in 100 000 [2], but there more classically, permanent atrial standc is not sufficient evidence on the prevalence still and junctional bradycardia, observed. of this condition in the Islamic Republic of Abnormalities in impulse generation or Iran. conduction are present in virtually all indic The 3 genetic patterns of EDMD are: viduals by age 35 to 40 years, and permac Xclinked recessive fashion (the commonest nent ventricular pacing is often required. form) produced by mutations in the emerin The severity of cardiac disease is much gene, which is located on the Xcchromoc greater than the myopathy [4]. some (Xq28); autosomal dominant; and This may explain arrhythmic and carc autosomal recessive. The 2 latter forms are diomyopathic presentation. The unique caused by mutations in the lamin A/C gene localization of emerin in desmosomes and on chromosome 1 (1q11–q23) [3]. fascia adherens of the intercalated disease The classic triad of symptoms of EDMD that functions in maintaining cellctoccell adc are: early contractures, particularly of the hesion and conduction may be responsible elbows, Achilles tendon, and posterior cerc for arrhythmic involvement [5]. vical muscles; cardiac conduction defects; The early onset of contractures before and slowly progressive weakness and atc the onset of any significant weakness is rophy in a humeroperoneal distribution unique to this disease. The elbows are genc [2]. Cardiac involvement can present with erally held in a semiflexed position, and the heart block, frequently inclate 20c or early child typically begins walking on tiptoe [2]. 30cyearcolds. Early signs are bradycardia 1Department of Physical Medicine and Rehabilitation; 2Department of Internal Medicine; 3Department of Orthopaedics; 4Department of Social Medicine, Yasuj University of Medical Sciences, Islamic Republic of Iran (Correspondence to P. Yazdanpanah: [email protected]). Received: 14/04/05; accepted: 05/07/05 202 La Revue de Santé de la Méditerranée orientale, Vol. 13, No 1, 2007 There are also contractures of other ligac Achilles tendons and decreased range of ments, including the metacarpals and other motion in the hips. Muscle strength grading smaller joints [6]. In EDMD serum creatine of elbow flexors was 3/5, shoulder abducc kinase (CK) level is normal or moderately tors 3/5 and other muscles 4/5. Sensory increased. examination was normal and deep tendon The course is generally benign, like that reflexes were 1/2. The patient showed wide of Becker muscular dystrophy, but weakc based gait and tiptoe walking. ness and contractures can be severe in some Electromyography was done, and all cases, and sudden death is a possibility [7]. nerve conduction readings (velocity, amc This disorder is considered a slowly proc plitude and latency) were normal. Needle gressive myopathy, but the disease spectrum electromyography showed polyphasicity, includes patients whose disease is much decreased duration and latency of motor more severe [8]. Some are unable to walk by unit, decreased to adequate recruitment. the time they reach adulthood, but survival Easy recruitment, specific to myopathy, is generally into middle age [9]. Treatment was seen in the gluteus maximus and delc is primarily focused on the cardiac disease, toid muscles. On the ECG there was atrial with a pacemaker being the typical form of flutter with 3:1 atrioventricular block. treatment. Bracing can also be helpful as the disease progresses. Early, frequent rangec Case 2 ofcmotion exercise and positioning are also The second case was the 3.5cyearcold brothc advisable and stretching exercises are indicc er of the first patient. He had had difficulty cated to minimize contractures [2,10]. walking (tiptoe walking) for 8 months (Figc This case report will augment informac ure 1). On physical examination there was tion about the course, genetic patterns and bilateral severe contracture of the Achilles complications of this rare disease and may tendons (Figure 1), positive Gower’s sign, help in better diagnosis and management, widecbased gait and normal sensory examic including the possibility of partial amelioc nation; deep tendon reflexes were 2/2. All ration of the cardiac and musculoskeletal the nerve conduction studies were normal. complications. Electromyography showed polyphasicity Cases Case 1 The patient is a 12cyearcold boy, referred with weakness of the muscles of the shoulc ders and arms. His main difficulty was contracture of the Achilles tendons, which began at 4 years of age with a diagnosis of “bilateral pes equinus deformity”. Surgery for release of the Achilles tendons had been done 8 years previously. Physical examination showed atrophy Figure 1 Ankle contracture in the second of the shoulder and arm muscles, positive patient, a boy 3.5 years old Gower’s sign, moderate contracture of the Eastern Mediterranean Health Journal, Vol. 13, No. 1, 2007 203 and decreased duration and amplitude of In EDMD, serum CK level is normal motor units in proximal muscles. Easy recc or moderately increased, but in Duchenne cruitment was seen in both gluteus maximus muscular dystrophy, it can be 300 to 400 muscles. The ECG of this patient (Figure 2) times greater than normal. Elevated CK is was similar to that of the first boy. noted in Becker muscular dystrophy, but it is usually lower than in boys with Duchenne Case 3 muscular dystrophy [2]. The third case was a girl 8 years old (the The signs and symptoms presented in sister of the 2 above cases) who was rec these 3 patients, primary contracture of the ferred with difficulty in walking and sitting; elbows and Achilles tendons, normal level and had been diagnosed with “bilateral pes of CK enzyme, cardiac involvement and abc equinus deformity” when surgery was done sence of pseudohypertrophy of calves, are for her 4 years ago. Physical examination more indicative of EDMD than Duchenne showed contracture of the Achilles tendons or Becker muscular dystrophies. and hips, and normal sensory examination; Another possible diagnosis is congenital deep tendon reflexes were 2/2 and there was myopathies, which are a group of nonproc weakness of the proximal muscles of the gressive or slowly progressive myopathies lower limbs. The electrophysiologic studc presenting with hypotonia or weakness ies and ECG of this patient were similar to in the neonatal period. Babies frequently those of the boys. have decreased spontaneous movement Serum CK levels for all 3 patients were and delayed motor milestone achievement. within the normal range. Muscles can feel flabby to palpation. Physicc The ECGs of the father and mother of cal anomalies such as high palate, pectus these patients were normal. excavatum, elongated face, and scoliosis can be present as an indication of longstandc ing weakness. CK level is usually normal Discussion [12]. Onset of disease occurring at around 4 EDMD is distinguishable clinically from years, contractures and absence of anomac the Duchenne and Becker forms by absence lies, however, support a diagnosis of EDMD of pseudohypertrophy of skeletal muscle, rather than congenital myopathy. The presc early involvement of the arms with elbow ence of contractures, normal amplitude contractures, and early onset cardiac conc of compound muscle action potentials on duction abnormalities and atrial dysrhythc nerve conduction studies, myopathic pattern mia [11]. Figure 2 Electrocardiogram of the second patient, a boy 3.5 years old, showing atrial flutter with 3:1 atrioventricular block 204 La Revue de Santé de la Méditerranée orientale, Vol. 13, No 1, 2007 of needle electromyography and cardiac formed of the diagnosis before any surgery involvement also suggest EDMD. is undertaken. Even though, the conduction system is Considering the genetic patterns of not primarily affected histologically, sudc EDMD (Xclinked recessive, autosomal den death is common in both hemizygous dominant or autosomal recessive), owing men and heterozygous women; thus, early to the equal chance of involvement in male detection can be life saving [13]. and females, the genetic pattern in this famc Patients with DMD and other myopac ily appears to be autosomal dominant. thies have been reported as having maligc Arrhythmia was present in all 3 of these nant hyperthermia as an adverse reaction patients. Permanent ventricular pacing is to general anaesthesia [2] and in EDMD recommended once conduction disease is patients the heart may be affected and could evident and can be life saving. Cardiac complicate an operation. Atrioventricular disease, including sudden death, remains block can also occur with anaesthesia [14]. responsible for significant mortality in The anaesthetist must, therefore, be inc EDMD despite early pacing [15]. References 1. Fowler WM, Nayak NN. Slowly progrest 8. Salmons S, Vrbova G. The influence of sive proximal weakness: limbtgirdle synt activity on some contractile characteristt dromes. Archives of physical medicine tics of mammalian fast and slow muscle. and rehabilitation, 1983;64(11):527–38. Journal of physiology, 1969, 201(3):535– 49. 2. Nelson MR. Rehabilitation concerns in myopathies. In: Randall LB. Physical 9. Hudlika O, Tyler KR. The effect of longt medicine and rehabilitation, 2nd ed. Philat term high frequency stimulation on capilt delphia, Saunders, 2000:1009–45. lary density and fiber types in rabbit fast muscles.
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