Allele-specific amplification for the diagnosis of autosomal recessive spinal muscular atrophy.

The SMN1 gene is homozygously deleted for at least exon 7, interrupted or converted to a non-functional telomeric copy in most cases of proximal spinal muscular atrophies. The presence of a pseudogene hampers direct detection of the exon 7 deletion. We describe a method for the detection of the of exon 7 deletion, based on the amplification refractory mutation system (ARMS), in a multiplex PCR with fluorescent-labelled primers. The gene and pseudogene amplification products differ in the dye bound and in their size, which allows distinction of both products on electrophoresis. The pseudogene is used as an internal control, and this method gives a clear and specific pattern for the patients. Amplification is achieved with 30 cycles, and specificity is retained up to 40 cycles.     

Studies on the carrier state in X-linked recessive (Duchenne) muscular dystrophy.

Observations in 12 normal women and 12 female carriers of X-linked recessive Duchenne muscular dystrophy (DMD), of whom 4 had symptoms and 8 had none, were compared between all 4 groups and with those in 2 DMD boys, one active and one crippled. Carrier symptoms were readily ascertained by systematic examination. Measurement of both lower legs in all 24 women showed neither calf enlargement nor asymmetry in carriers beyond normal variation. Two DMD carrier daughters were noted of the same DMD carrier mother but by different fathers. Whole body counting showed the biological half-life of previously administered 86Rb to be much reduced in DMD, but no differences were found between normal women and any group of carriers. The test is thus valueless for carrier detection, and reasons are given why it should be so. Simultaneous measurement of total body K+, with subsequent determination by isotope dilution of total body water as 3H2O space and extracellular water as NH4 82Br space, showed increased intracellular water and reduced intracellular K+ concentration in all carriers, as if due to osmotic causes, with actual loss of muscle mass and slight diminution of serum K+ in the 4 symptomatic carriers only. Because of diurnal and other variations, the means and standard deviations for six serum enzymes from six fortnightly assays in all subjects were used to measure precise individual status. Their coefficients of variation were abnormal only in symptomatic carriers and ambulant DMD, easily overtexed by even accustomed exertion. This is shown to support previous propositions on the pathogenesis of DMD and the escape of muscle cell content into the circulation.     

The value of orthoses for patients with Duchenne muscular dystrophy.

We applied knee-ankle-foot orthoses to 17 consecutive patients with Duchenne muscular dystrophy at the time they lost independent ambulation. We judged the value of the orthoses solely by the patients' ability to walk. With the orthoses, 7 patients (41%) became effective ambulators and benefited greatly from the appliances. Four patients (23%) had borderline results. Six patients (35%) were considered failures because they achieved only braced standing. We believe orthoses are indicated for many but not all patients with Duchenne muscular dystropy.     

Evoked muscle action potentials in patients with muscular dystrophy

Electromyographic study of evoked muscle action potentials was made in a group of 31 patients with muscular dystrophy. Potentials, recorded with bipolar needle electrodes, were evoked by supramaximal stimuli applied to the motor nerve. The potentials recorded in 21 (67.7%) patients appeared markedly polyphasic, with a considerable degree of temporal dispersion. In general, the average number of phases was 20.9 +/- 9.08; the average duration attained 29.1 +/- 10.57 msec. The latency for the first component of the potentials and the motor conduction velocity along the main trunks were normal. The polyphasic potentials of dystrophic patients were similar to the MAP evoked in neuropathic patients. It is concluded that the long-lasting polyphasic potentials of dystrophic patients may represent the involvement of the thin peripheral branches of motor nerves in the pathologic process.     

Reliability of goniometric measurements in patients with Duchenne muscular dystrophy

Previous studies of reliability of goniometric measurements have produced varied findings suggesting the need to document further the reliability of measuring range of motion in different patient groups. The purpose of this study was to determine the intratester and intertester reliability of goniometric measurements of seven common upper and lower extremity joint limitations in children with Duchenne muscular dystrophy. Five physical therapists participated in the study. The procedure and order of measurements were standardized. Results showed that intratester reliability for all measurements was high (ICC = .81 to .94), but intertester reliability showed a wide variation (ICC = .25 to .91). The results of this study indicate the need to use the same examiner for long-term follow-up and for assessing results of specific treatment interventions.     

进行性假肥大性肌营养不良患者康复现状调查

目的 调查进行性假肥大性肌营养不良(DMD)患者康复情况与需求。方法 对2018年10月至2022年3月就诊于安徽医科大学武警总医院DMD门诊患者进行基本信息和康复情况问卷调查。结果 共发放问卷963份,回收有效问卷944份(98.0%)。患者均为男性,年龄5～27岁,平均(9.24±0.184)岁;710例可独立行走;140例定期到专业机构进行康复训练,618例规律进行有氧运动,416例规律进行关节拉伸训练,292例规律使用辅助器具。538例对康复效果不满意,658例存在康复知识获取困难。Logistic回归显示,规律进行康复锻炼的患者丧失独立行走能力的风险下降(OR <0.61, P <0.05)。结论 DMD患者有较为广泛的康复需求,但有氧运动锻炼率、关节拉伸训练率和辅助器具使用率较低,可能影响患者运动功能和生活质量。     

Defective expression of plectin/HD1 in epidermolysis bullosa simplex with muscular dystrophy.

Epidermolysis bullosa simplex with muscular dystrophy (MD-EBS) is a disease characterized by generalized blistering of the skin associated with muscular involvement. We report that the skin of three MD-EBS patients is not reactive with antibodies 6C6, 10F6, or 5B3 raised against the intermediate filament-associated protein plectin. Immunofluorescence and Western analysis of explanted MD-EBS keratinocytes confirmed a deficient expression of plectin, which, in involved skin, correlated with an impaired interaction of the keratin cytoskeleton with the hemidesmosomes. Consistent with lack of reactivity of MD-EBS skin to plectin antibodies, plectin was not detected in skeletal muscles of these patients. Impaired expression of plectin in muscle correlated with an altered labeling pattern of the muscle intermediate filament protein desmin. A deficient immunoreactivity was also observed with the monoclonal antibody HD121 raised against the hemidesmosomal protein HD1. Furthermore, immunofluorescence analysis showed that HD1 is expressed in Z-lines in normal skeletal muscle; whereas this expression is deficient in patient muscle. Colocalization of HD1 and plectin in normal skin and muscle, together with their impaired expression in MD-EBS tissues, strongly suggests that plectin and HD1 are closely related proteins. Our results therefore provide strong evidence that, in MD-EBS patients, the defective expression of plectin results in an aberrant anchorage of cytoskeletal structures in keratinocytes and muscular fibers leading to cell fragility.     

Restoration of LDL receptor function in cells from patients with autosomal recessive hypercholesterolemia by retroviral expression of ARH1

Familial hypercholesterolemia is an autosomal dominant disorder with a gene-dosage effect that is usually caused by mutations in the LDL receptor gene that disrupt normal clearance of LDL. In the homozygous form, it results in a distinctive clinical phenotype, characterized by inherited hypercholesterolemia, cholesterol deposition in tendons, and severe premature coronary disease. We described previously two families with autosomal recessive hypercholesterolemia that is not due to mutations in the LDL receptor gene but is characterized by defective LDL receptor-dependent internalization and degradation of LDL by transformed lymphocytes from the patients. We mapped the defective gene to chromosome 1p36 and now show that the disorder in these and a third English family is due to novel mutations in ARH1, a newly identified gene encoding an adaptor-like protein. Cultured skin fibroblasts from affected individuals exhibit normal LDL receptor activity, but their monocyte-derived macrophages are similar to transformed lymphocytes, being unable to internalize and degrade LDL. Retroviral expression of normal human ARH1 restores LDL receptor internalization in transformed lymphocytes from an affected individual, as demonstrated by uptake and degradation of (125)I-labeled LDL and confocal microscopy of cells labeled with anti-LDL-receptor Ab.     

Functional defect in neutrophil cytosols from two patients with autosomal recessive cytochrome-positive chronic granulomatous disease.

The kinetics of activation of the respiratory burst oxidase in the cell-free oxidase-activating system have been explained by a three-stage mechanism in which the membrane-associated oxidase components M: (a) take up a cytosolic factor S to form a complex M.S that is (b) slowly converted in the second stage to a precatalytic species [M.S]*, which finally (c) takes up two more (possibly identical) cytosolic components, C alpha and C beta, to successively generate [M.S]*C alpha, a low-activity (i.e., high Km) oxidase, and finally [M.S]*C alpha C beta, the ordinary (i.e., low Km) oxidase (Babior, B.M., R. Kuver, and J.T. Curnutte. 1988. J. Biol. Chem. 263:1713-1718). Studies with the cell-free oxidase-activating system from normal neutrophils and from neutrophils obtained from two patients with type II (autosomal recessive cytochrome-positive) chronic granulomatous disease (CGD) have suggested that (a) the defective element in the cytosol from patient neutrophils is S; (b) in normal neutrophil cytosol, S is limiting with respect to M; and (c) C alpha and C beta interact cooperatively with the activated precursor complex [M.S]*. It was further speculated that S might be identical to the nonphosphorylated progenitor of the phosphorylated 48-kD proteins that are missing in certain forms of CGD, and that other forms of type II CGD besides the one described in this report remain to be discovered.     

Wheelchair-mounted robot manipulators. Long term use by patients with Duchenne muscular dystrophy

This report relays practical clinical information about the modification and use of commercially available training robot manipulators. Such manipulators were used to increase independence in the activities of daily living of patients with advanced Duchenne muscular dystrophy. The control panels of five industrial robot manipulator training devices were modified for use by advanced Duchenne muscular dystrophy patients. Six patients with only residual finger movement, three of whom were dependent on respiratory support, mastered the use of these devices. The four patients with long-term access employed their manipulators for facilitation of activities of daily living an average of 8 h a day for 3 +/- 1.8 yr. There was approximately 3 h of estimated attendant care time saved per patient per day.     

假肥大型肌营养不良患者肌型肌酸激酶亚型的临床研究

目的：研究假肥大型肌营养不良（ＤＭＤ）患者肌型酸激酶（ＣＫ－ＭＭ）亚型的变化，为早期诊断和评价病情提供依据。方法：采用不连续缓冲体系，在稳流低压下条件下电泳，将ＣＫ－ＭＭ亚型分离、荧光扫描。结果：ＤＭＤ患者在不同阶段的ＣＫ－ＭＭ亚型值均与对照组相比有显著性差异（Ｐ〈０．０５）；ＤＭＤ患者不同阶段的ＭＭ２／ＭＭ１值也有显著性差异（Ｐ〈０．０５）。结论：ＣＫ－ＭＭ亚型的改变是ＤＭＤ患者诊断及判断病情的