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We reported a fetus with limb abnormalities and abnormal ultrasound soft markers diagnosed with nemaline myopathy. A pregnant woman (G1P0) underwent amniocentesis at 18 +2 gestational weeks due to thickened nuchal translucency suggested by ultrasound at 13 +5 gestational weeks. Karyotyping and single nucleotide polymorphism array of the amniotic fluid cells showed no fetal abnormalities. However, ultrasonographic reexaminations at 23, 28, and 28 +1 weeks indicated limb abnormalities and thickened nuchal fold, and the pregnant woman chose to terminate the pregnancy at 29 +2 gestational weeks. Whole exome sequencing showed compound heterozygous mutations of c.602G>A (p.W201*) and c.1516A>C (p.T506P) in the KLHL40 gene inherited from the mother and the father, respectively, resulting in nemaline myopathy type 8.
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Objective To study the clinical and pathological features of nemaline myopathy(NM) in 12 cases.Methods Clinical manifestations and pathological features of muscle-biopsy specimens were summarized and analyzed retrospectively in 12 NM cases.Results In 12 cases,7 patients with typical congenital type exhibited lower or four limbs weakness as the first symptom and benign course.Three patients with childhood onset type exhibited lower limbs weakness and progressive course,and this type of patient might have muscle atrophy.Two patients with adult onset type exhibited four limbs and throat muscle weakness,rapidly progressive course and obvious muscle atrophy,and one patient had already shown acute respiratory failure.High arched feet and elongated face were observed.Creatin kinase value in all patients was normal or mildly elevated,and all electromyography showed myogenic changes.In light microscopy,the nemaline bodies were observed in more than half muscle fibers,especially in type 1 fibers.All patients showed type 1 predominance and atrophy.Modified Gomori trichrome stains showed characteristic purplecolored rods.Muscle electron microscopy showed high electron dense nemaline bodies around nucleus and disorganized myofibrillar apparatus such as broken myofilaments,irregular myofibril and Z lines.Nemaline bodies under electron microscopy may be part of myofibril or high electron-dense bodies with no structure.Conclusions The 12 patients in this study with NM are divided into 3 types,of which adult onset type is the most severe one.The key diagnosis is based on the appearance of nemaline bodies in more than half of the muscle fibers and the muscle electron microscopy observation.
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Objective To investigate the clinical and pathological features of adult form nemaline myopathy. Methods Biopsied muscle specimens from two patients were observed using enzymatic histochemical method and electron microscope. Results These two patients were found with an initial onset from neck muscle weakness at the age of 52 and 36 years respectively, followed by trunk and limb muscle involvement to a variant degree. Type Ⅰ fiber atrophy and numerous granules (rod) were found in both patients in light microscopy. In case 1, the centralized nuclei were seen almost in all normal sized muscle fibers. Electron microscopic observation showed marked myofibril disorganization and numerous rod-like formations. Two inclusion-carrying nuclei were detected in case 1. The intranuclear inclusion showed a lattice pattern of Z-disc line or sarcoplasmic rod. Conclusions Adult form nemaline myopathy is clinically nonspecific. Rod-like structures might be found either in sarcoplasma or in nucleus. Centralized nuclei might coexist with rods in adult form nemaline myopathy. As compared to the child form, the adult one might often show a marked muscle fiber atrophy.