PURPOSE: Floppy infant, or congenital hypotonia, is caused by various diseases, such as genomic disorders, diseases involving the central or peripheral nervous system, musculoskeletal diseases, and metabolic disorders. We describe here the clinical aspects and the final diagnosis of infants with hypotonia recently diagnosed in a single, tertiary-care hospital in Korea. METHODS: All of the infants evaluated for generalized hypotonia between 2008 and 2012 at Asan Medical Center Children's Hospital were included in our study. The demographic data, physical examination upon initial presentation, the diagnostic tests and results, and the final diagnosis were retrospectively reviewed. RESULTS: A total of 128 infants (68 males, 60 females) were included in the study, and the mean patient age at the time of the diagnosis of hypotonia was 4.8 months. Etiological diagnosis was possible in 80 (62.5%) of the 128 patients, and 57 (44.5%) patients were confirmed by genetic testing. Fifteen patients (11.7%) were categorized as having central nervous system disorders, and 34 (26.6%) patients were diagnosed as having other genomic disorders such as Prader-Willi syndrome (n=17). Disease involving muscle and the peripheral nervous system was detected in 16 (12.5%) patients. Five patients were diagnosed with other skeletal disorders, and metabolic disease was detected in 10 (7.8%) patients. CONCLUSION: With the recent advances in diagnostic tools, including genetic testing, many of the patients with hypotonia can be correctly diagnosed. These data can give practical clues regarding the optimal diagnostic approaches for treating floppy infants in the clinics.
Central Nervous System Diseases ; Chungcheongnam-do ; Diagnosis ; Diagnostic Tests, Routine ; Genetic Testing ; Genetics ; Humans ; Infant* ; Korea ; Male ; Metabolic Diseases ; Muscle Hypotonia ; Musculoskeletal Diseases ; Peripheral Nervous System ; Physical Examination ; Prader-Willi Syndrome ; Retrospective Studies

Mutations causing genetic disorders can occur during mitotic cell division after fertilization, which is called somatic mutations. This leads to somatic mosaicism, where two or more genetically distinct cells are present in one individual. Somatic mutations are the most well studied in cancer where it plays an important role and also have been associated with some neurodegenerative disorders. The study of somatic mosaicism in Parkinson disease (PD) is only in its infancy, and a case with somatic mutation has not yet been described. However, we can speculate that a somatic mutation affecting cells in the central nervous system including substantia nigra dopaminergic neurons could lead to the development of PD through the same pathomechanisms of genetic PD even in the absence of a germ-line mutation. Theoretically, a number of genes could be candidates for genetic analysis for the presence of somatic mosaicism. Among them, SNCA and PARK2 could be the best candidates to analyze. Because analyzing brain tissues in living patients is impossible, alternative tissues could be used to indicate the genetic status of the brain. Performance of the technology is another factor to consider when analyzing the tissues.
Brain ; Cell Division ; Central Nervous System ; Dopaminergic Neurons ; Fertilization ; Genetics ; Germ-Line Mutation ; Humans ; Mosaicism* ; Neurodegenerative Diseases ; Parkinson Disease* ; Substantia Nigra

Enterovirus 71 frequently involves the central nervous system and may present with a variety of neurologic manifestations. Here, we aimed to describe the clinical features, magnetic resonance imaging (MRI) findings, and cerebrospinal fluid (CSF) profiles of patients presenting with neurologic complications of enterovirus 71 infection. We retrospectively reviewed the records of 31 pediatric patients hospitalized with acute neurologic manifestations accompanied by confirmed enterovirus 71 infection at Ulsan University Hospital between 2010 and 2014. The patients' mean age was 2.9 ± 5.5 years (range, 18 days to 12 years), and 80.6% of patients were less than 4 years old. Based on their clinical features, the patients were classified into 4 clinical groups: brainstem encephalitis (n = 21), meningitis (n = 7), encephalitis (n = 2), and acute flaccid paralysis (n = 1). The common neurologic symptoms included myoclonus (58.1%), lethargy (54.8%), irritability (54.8%), vomiting (48.4%), ataxia (38.7%), and tremor (35.5%). Twenty-five patients underwent an MRI scan; of these, 14 (56.0%) revealed the characteristic increased T2 signal intensity in the posterior region of the brainstem and bilateral cerebellar dentate nuclei. Twenty-six of 30 patients (86.7%) showed CSF pleocytosis. Thirty patients (96.8%) recovered completely without any neurologic deficits; one patient (3.2%) died due to pulmonary hemorrhage and shock. In the present study, brainstem encephalitis was the most common neurologic manifestation of enterovirus 71 infection. The characteristic clinical symptoms such as myoclonus, ataxia, and tremor in conjunction with CSF pleocytosis and brainstem lesions on MR images are pathognomonic for diagnosis of neurologic involvement by enterovirus 71 infection.
Acute Disease ; Brain/diagnostic imaging ; Central Nervous System Diseases/etiology/*pathology ; Child ; Child, Preschool ; Encephalitis/pathology ; Enterovirus A, Human/genetics/*isolation & purification ; Enterovirus Infections/drug therapy/*pathology/virology ; Feces/virology ; Female ; Humans ; Immunoglobulins/administration & dosage ; Infant ; Injections, Intravenous ; Leukocytes/cytology ; Leukocytosis/cerebrospinal fluid/pathology ; Magnetic Resonance Imaging ; Male ; RNA, Viral/genetics/metabolism ; Real-Time Polymerase Chain Reaction ; Republic of Korea ; Retrospective Studies ; Seasons

Due to the therapeutic potential of gene therapy for neuronal injury, many studies of neurotrophic factors, vectors, and animal models have been performed. The presumed dog beta-nerve growth factor (pdbeta-NGF) was generated and cloned and its expression was confirmed in CHO cells. The recombinant pdbeta-NGF protein reacted with a human beta-NGF antibody and showed bioactivity in PC12 cells. The pdbeta-NGF was shown to have similar bioactivity to the dog beta-NGF. The recombinant pdbeta-NGF plasmid was administrated into the intrathecal space in the gene therapy group. Twenty-four hours after the vector inoculation, the gene therapy group and the positive control group were intoxicated with excess pyridoxine for seven days. Each morning throughout the test period, the dogs' body weight was taken and postural reaction assessments were made. Electrophysiological recordings were performed twice, once before the experiment and once after the test period. After the experimental period, histological analysis was performed. Dogs in the gene therapy group had no weight change and were normal in postural reaction assessments. Electrophysiological recordings were also normal for the gene therapy group. Histological analysis showed that neither the axons nor the myelin of the dorsal funiculus of L(4) were severely damaged in the gene therapy group. In addition, the dorsal root ganglia of L(4) and the peripheral nerves (sciatic nerve) did not experience severe degenerative changes in the gene therapy group. This study is the first to show the protective effect of NGF gene therapy in a dog model.
Amino Acid Sequence ; Animals ; Base Sequence ; CHO Cells ; Central Nervous System Diseases/chemically induced/therapy/*veterinary ; Cloning, Molecular ; Cricetinae ; Cricetulus ; Cytomegalovirus ; Dog Diseases/*chemically induced/therapy ; Dogs ; Female ; Gene Therapy/*veterinary ; Genetic Vectors ; Male ; Molecular Sequence Data ; Nerve Growth Factor/genetics/*metabolism/*therapeutic use ; Pyridoxine/*toxicity