OBJECTIVE: To investigate the clinical features and genetic variants associated with Multiple mitochondrial dysfunction syndrome (MMDS) type 3 in two children. METHODS: Two children diagnosed with MMDS type 3 at Zhuhai Maternal and Child Health Care Hospital in January 2021 were selected for this study. A retrospective analysis of their clinical data was carried out. Whole exome sequencing was conducted on the two children and their parents, followed by Sanger sequencing for candidate variants and bioinformatic analysis. Both children received comprehensive rehabilitative therapy and were followed up for 3 years. This study was approved by the Ethics Committee of Zhuhai Maternal and Child Health Hospital (Ethics No. 202380). RESULTS: The two MMDS type 3 children were monozygotic twin girls, aged 9 months, presenting with developmental regression, pyramidal signs, and other clinical manifestations. Cranial MRI revealed widespread abnormal signals and vacuolar changes in the white matter. Whole exome sequencing revealed that both children had harbored compound heterozygous variants of the IBA57 gene, namely c.286T>C (p.Tyr96His) and c.307C>T (p.Gln103Ter). Sanger sequencing confirmed that these variants were inherited from their father and mother, respectively. According to the American College of Medical Genetics and Genomics (ACMG) guidelines, both variants were classified as pathogenic (PM2_Supporting+PM3_Very Strong+PP3_Moderate; PVS1+PM2_Supporting+PM3). After treatment with vitamins, levocarnitine, ATP, coenzyme Q10, and other drugs, both children showed partial recovery of neurodevelopmental regression, with improvement in feeding and sleep. Over the 3-year follow-up, there was slow but progressive improvement in motor, language, and cognitive development. CONCLUSION The compound heterozygous variants c.286T>C (p.Tyr96His) and c.307C>T (p.Gln103Ter) of the IBA57 gene probably underlay the MMDS type 3 in the twin pair. Clinicians should be vigilant about the possibility of MMDS type 3 in children with neurodevelopmental regression and early cranial MRI findings indicating widespread white matter abnormalities with vacuolar changes, as these may be indicative of IBA57 gene variants.
Female ; Humans ; Infant ; Calcium-Binding Proteins/genetics* ; Exome Sequencing ; Genetic Testing/methods* ; Microfilament Proteins/genetics* ; Mitochondrial Diseases/genetics* ; Mutation ; Retrospective Studies ; Carrier Proteins

OBJECTIVE: To discuss the advantages and technical limitations of various molecular genetic techniques in the diagnosis of two infants featuring all-round developmental retardation. METHODS: The two patients were initially screened by using chromosomal microarray analysis (CMA). For patient 1, his parents were also subjected to CMA analysis, and the data was analyzed by using ChAS and UPD-tool software. For patient 2, methylation-specific PCR (MS-PCR) was carried out. RESULTS: Patient 1 was diagnosed with maternal uniparental disomy (UPD) type Prader-Willi syndrome (PWS) by CMA and UPD-tool family analysis. His chromosomes 15 were of maternal UPD with homology/heterology. Patient 2 was diagnosed with deletion type PWS by combined CMA and MS-PCR. CONCLUSION Correct selection of laboratory methods based on the advantages and limitations of various molecular techniques can help with diagnosis of genomic imprinting disorders and enable better treatment and prognosis through early intervention.

ObjectiveTo explore temperament characteristics of children with cerebral palsy.Methods364 children with cerebral palsy, ages from four months to seven years, were tested with modified Carey\'s Children Temperament Questionnaires. Temperament characteristics of children with different types of cerebral palsy, able and unable walk independently were compared.ResultsChildren with cerebral palsy had negative temperament including less active, low persistence, high distractibility and negative mood. Approach was different between children with diplegia and athtosis. There were no different temperaments among children with different lever of IQ. Children they could not walk independently had an obvious negative temperament.ConclusionChildren with cerebral palsy have significantly negative temperament.