PURPOSE:To investigate mitochondrial DNA(mtDNA) of Leber's hereditary optic neuropathy(LHON). METHODS:Polymerase chain reaction(PCR)method was used to analyse mtDNA of 11 patients in a pedigree with LHON and 4 control subjects from none LHON pedigree. RESULTS:There was a loss of a restriction site for the restriction endonuclease SfaN.Ⅰin Ihe Patients with LHON. In this pedigree,maternal lineage was regarded a carrier of the pathogenic gene. CONCLUSIONS:The patients with Leber's hereditary optic neuropathy have a point mutation in mtDNA,which results in loss ol SfaN I endonuclease restriction site .and this change is one of mechanisms inducing this disaese. （Chin J Ocul Fundus Dis,1997,13: 27-29）
Objective To investigate the impact of genetic and environmental factors on mental health status and to estimate the prevalence of subclinical psychiatric symptoms and psychological problems in child and adolescent twins, by using the Strengths and Difficulties Questionnaire (SDQ). Methods A total of 59 pairs of twins aged 6-16 years were recruited with support from educational committees and schools. After the guardians of these twins had signed an informed consent form, SDQ were completed by the parents and teachers of these twins to investigate their mental health status. Buccal mucosa samples were collected from all twins for DNA extraction and zygosity identification test. Results The intrapair correlation coefficients of monozygotic twins were significantly different from those of dizygotic twins in terms of emotional symptoms, inattention-hyperactivity, peer problems, impact and diagnostic predictions (including any psychiatric disorder, emotional disorder, oppositional/conduct disorders, ADHD/hyperkinesis). The results from the SDQ screening questionnaire showed that up to 37.5% of the studied twins were suffering from a psychiatric disorder, including emotional disorder (5.5%), oppositional/conduct disorder (29.7%), and ADHD/hyperkinesis (14.8%).Conclusion Genes plays an important role in the mental health status of child and adolescent twins. More attention should be paid to the mental development and mental health in these twins, because of the considerable prevalence of subclinical psychiatric symptoms and psychological problems.
ObjectiveTo investigate the clinical characteristics and genetic phenotype of mitochondrial myopathy associated with lactic acidemia and stroke-like seizure syndrome (MELAS) in DNA A3243G mutation, and to improve the clinical understanding and diagnosis.MethodsThe clinical data and imaging characteristics of 4 patients with DNA A3243G mutation-related MELAS syndrome who were diagnosed and treated in the Department of Pediatric Neurology, Henan Provincial People's Hospital from June 2017 to June 2018 were retrospectively reviewed.ResultsOf the 4 patients, 3 were caused by convulsions, 1 was caused by dizziness, and the MELAS syndrome caused by mitochondrial DNA A3243G mutation was confirmed by genetic testing. The patients were treated with anti-epilepsy drugs. The patients were followed up for at least 1 year, and 2 of 4 patients were stable, 1 patient still had seizures, and 1 patient did not improved.ConclusionsThe clinical phenotypic heterogeneity of patients with DNA A3243G mutation-related MELAS syndrome is caused by the " heterogeneity” and " threshold effect” of DNA mutation. The mutation rate of DNA A3243G is as high as 80%. In the era of promoting precision medicine, genes examination can help early diagnosis and early treatment of MELAS syndrome as well as improve the quality of life of patients and improve the prognosis.