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Regular health checkups for mothers of patients with Duchenne muscular dystrophy have been performed at National Hospital Organization Tokushima Hospital since 1994. Among 43 mothers participated in this study, 28 dystrophinopathy carriers were identified. Skeletal and cardiac muscle functions of these subjects were examined. High serum creatine kinase was found in 23 subjects (82.1%). Obvious muscle weakness was present in 5 (17.8%) and had progressed from 1994 to 2015. Cardiomyopathy was observed in 15 subjects (60.0%), including dilated cardiomyopathy-like damage that was more common in the left ventricular (LV) posterior wall. Late gadolinium enhancement on cardiac MRI was found in 5 of 6 subjects, suggesting fibrotic cardiac muscle. In speckle tracking echocardiography performed seven years later, global longitudinal strain was decreased in these subjects, indicating LV myocardial contractile abnormality. These results suggest that female dystrophinopathy carriers should receive regular checkups for detection and treatment of cardiomyopathy, even if they have no cardiac symptoms.

In this study, we compared the clinicopathological findings of two autopsy cases of patients with calpainopathy (LGMD2A) from different families. The patient in case 1 was a 72-year-old man with a history of type 2 diabetes mellitus. He exhibited recent memory impairments from the age of 70. ECG revealed an incomplete right bundle branch block. A homozygous frameshift mutation c.1796dupA was found in the CAPN3 gene. Cause of death was respiratory insufficiency and heart failure. The patient in case 2 was a 70-year-old man with a history of hypertension. ECG revealed an incomplete right bundle branch block. A homozygous missense mutation c.1080GC (p.Trp360Cys) in CAPN3 gene was identified. Cause of death was ischemic cardiomyopathy and systemic circulatory failure. In both cases, muscle pathology revealed severe dystrophic changes. In case 2, cardiac hypertrophy and old myocardial infarcts with stenosis of coronary arteries were observed. Histological examination of the sinoatrial node showed fatty infiltration with ischemic changes in case 2. In both cases, the patients' brains showed cerebral atrophy and well preserved neurons. Calpain 3 abnormality was correlated with skeletal muscle involvement. It should be considered that LGMD2A might be complicated by dysfunction of the cardiac conduction system.

We report on the clinical, pathological, and genetic features of 7 patients with limb-girdle muscular dystrophy type 2A (LGMD2A) from three Japanese families. The mean age of onset was 9.7+/-3.1 years (mean+/-SD), and loss of ambulance occurred at 38.5+/-2.1 years. Muscle atrophy was predominant in the pelvic and shoulder girdles, and proximal limb muscles. Muscle pathology revealed dystrophic changes. In two families, an identical G to C mutation at position 1080 the in calpain 3 gene was identified, and a frameshift mutation (1796insA) was found in the third family. The former mutation results in a W360R substitution in the proteolytic site of calpain 3, and the latter in a deletion of the Ca2+-binding domain.

The level of plasma brain natriuretic peptide (BNP) was elevated in 8 of 15 female gene carriers of Duchenne muscular dystrophy (DMD), and the level correlated with indices of cardiac function. In one of these carriers, whose clinical course was followed for one year, the plasma BNP level was elevated before the development of cardiac symptoms, further increased with the evolution of cardiac symptoms, and then decreased after treatment for cardiac failure. These results suggest that the plasma BNP level may be useful for the early detection of cardiac dysfunction and for evaluating the efficacy of cardiac treatment in female DMD carriers.

Homozygous adhalin gene mutations were found in three patients from two consanguineous families with autosomal recessive childhood onset muscular dystrophy. Muscle biopsies from patients in each family showed complete absence of adhalin. Sequencing of adhalin cDNA prepared from skeletal muscle by reverse transcription PCR demonstrated a cytosine to thymidine substitution at nt 229 in the patient in family 1 and an adenine to guanine substitution at nt 410 and a 15-base insertion between nt 408 and 409 in the two patients in family 2. Sequencing of genomic DNA prepared from peripheral blood leukocytes by PCR confirmed these mutations. The parents in each family were found to be heterozygous for the respective mutations. These adhalin gene mutations are presumed to be responsible for the absence of adhalin in the skeletal muscle. Adhalin deficiency likely causes disruption of the muscle cell membrane, resulting in dystrophic changes in the skeletal muscle similar to dystrophin deficiency in Duchenne muscular dystrophy.

Activities of nine lysosomal enzymes and pH-dependent isozyme patterns of α-mannosidase were examined in the skeletal muscle of patients with neuromuscular diseases, and the ratios of these enzyme activities in leukocytes to those in myocytes (UM ratio) were determined. The activities of enzymes with a high UM ratio were markedly increased in the muscles of patients with Duchenne muscular dystrophy (DMD), myotonic dystrophy (MyD), or polymyositis (PM). In contrast, those which showed a low UM ratio were increased in the muscles of amyotrophic lateral sclerosis (ALS) and disuse muscle atrophy (DUA). The isozyme pattern of α-mannosidase in DMD muscle resembled that in leukocytes, while those in ALS and DUA muscle resembled that in normal muscle. These results may suggest that the increased activity of lysosomal enzymes in the muscles of patients with DMD, MyD, or PM is due primarily to infiltrating leukocytes, while that in patients with ALS or DUA is due to intramyofiber lysosomes. 1995 John Wiley & Sons, Inc. . neuromuscular disease MUSCLE & NERVE 18 :1009-10151995

To investigate the possible relationship of HTLV-I virus infection to autoimmune thyroid disease, we examined, firstly, the frequency of HTLV-I seropositivity among patients with Hashimoto's thyroiditis and, secondly, the frequency of Hashimoto's thyroiditis in patients with HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). Of 144 patients with Hashimoto's thyroiditis in the Tokushima and Kochi Prefectures, Japan, 9 (6.3%) were positive for serum HTLV-I virus antibody 2 of whom were confirmed histologically to have Hashimoto's thyroiditis. This percentage is significantly higher (P < 0.01) than the estimated prevalence (2.2%) of HTLV-I carriers among the general population in this region. Of 9 patients with HAM/TSP, 3 (33.3%), including 2 biopsy-proven cases, had evidence of Hashimoto's thyroiditis. This proportion is apparently much higher than the prevalence (1.7%) of Hashimoto's thyroiditis in the general population. These findings suggest that HTLV-I virus may be related to the development of Hashimoto's thyroiditis. © 1992 Wiley-Liss, Inc.