Search

Variations in mitochondrial genome have been found to be associated with hearing loss. Of these, the mitochondrial 12S rRNA and tRNASer(UCN) are the hot-spots for pathogenic variants associated with deafness. To understand the putative role of mitochondrial DNA (mtDNA) variants in hearing loss, we recently screened the variants in mitochondrial genomes in patients with deafness from the Hangzhou area of Zhejiang Province, People’s Republic of China (PRC). In this study, we describe a maternally-inherited Han Chinese family with high penetrance of hearing loss, notably, the penetrance of hearing loss in this family were 80.0 and 40.0%, when the aminoglycoside was included or excluded. Three matrilineal relatives in this pedigree exhibited different levels of hearing loss with different age at onset. In addition, sequence analysis of the complete mitochondrial genome showed the presence of the well-known C1494T pathogenic variant in the 12S rRNA gene and the G7444A pathogenic variant in the COI/ tRNASer(UCN). The C1494T anomaly had been reported to be a pathogenic mutation associated with aminoglycoside-induced and nonsyndromic hearing loss (AINHL), while the G7444A was considered as a secondary mutation associated with deafness. However, the lack of functional variants in GJB2 and TRMU genes suggested that nuclear modified genes may not play important roles in deafness expression. Thus, the combination of G7444A and C1494T pathogenic variants in the mitochondrial genome may account for the high penetrance of hearing loss in this Chinese family.

Variations in mitochondrial genome have been found to be associated with hearing loss. Of these, the mitochondrial 12S rRNA and tRNASer(UCN) are the hot-spots for pathogenic variants associated with deafness. To understand the putative role of mitochondrial DNA (mtDNA) variants in hearing loss, we recently screened the variants in mitochondrial genomes in patients with deafness from the Hangzhou area of Zhejiang Province, People's Republic of China (PRC). In this study, we describe a maternallyinherited Han Chinese family with high penetrance of hearing loss, notably, the penetrance of hearing loss in this family were 80.0 and 40.0%, when the aminoglycoside was included or excluded. Three matrilineal relatives in this pedigree exhibited different levels of hearing loss with different age at onset. In addition, sequence analysis of the complete mitochondrial genome showed the presence of the well-known C1494T pathogenic variant in the 12S rRNA gene and the G7444A pathogenic variant in the COI/ tRNASer(UCN). The C1494T anomaly had been reported to be a pathogenic mutation associated with aminoglycosideinduced and nonsyndromic hearing loss (AINHL), while the G7444A was considered as a secondary mutation associated with deafness. However, the lack of functional variants in GJB2 and TRMU genes suggested that nuclear modified genes may not play important roles in deafness expression. Thus, the combination of G7444A and C1494T pathogenic variants in the mitochondrial genome may account for the high penetrance of hearing loss in this Chinese family. [ABSTRACT FROM AUTHOR]

Objective: To investigate the diagnosis and management of laryngeal cleft. Method: The clinical data of 13 cases of laryngeal cleft treated between 2007 and 2015 was analyzed retrospectively. Results: The children with laryngeal cleft were classified according to the classification of Benjamin-Inglis, as type Ⅰ(11 cases), typeⅡ(1 case) and type Ⅲ(1 case). All patients were confirmed by microlaryngobronchoscopy under general anaesthetic. Eleven typeⅠ and 1 type Ⅱ clefts were managed conservatively, with which all type Ⅰ patients were successfully managed, while the type Ⅱ patient was resolved by surgical endoscopy. The type Ⅲ patient was treated by open repair but the results was poor. Conclusions: Patients who suffered with choking on feeding or recurrent aspiration pneumonia, especially coexisted with other congenital malformation, needed detailed evaluation for laryngeal cleft, although which was a rare congenital abnormality. Electronic laryngoscope could be the first step to screen the cleft, while microlaryngobronchoscopy is the gold standard for diagnosis of laryngeal cleft. The majority of children with lower type clefts can be managed conservatively. Surgical endoscopy has high success rate when strictly following the indication. Type Ⅲ and Ⅳ clefts have high mortality for usually combining with severe complications and abnormalities.

Objective: To analyze the causes and management plan of pediatric spontaneous tonsillar haemorrhage(STH). Methods: According to the criteria of STH difined by Griffies, patients with STH from December 2013 to January 2016 were included in this retrospective study. Results: A total of 11 patients were reviewed. The etiological diagnosis included 3 pediatric Epstein-Barr virus associated infectious mononucleosis(EBV-IM), 3 suspected pediatric EBV-IM to 3 acute suppurative tonsillitis, 1 acute viral tonsillitis and 1 hemophilia A. The management strategies included antiviral, antibacteria, transfusion, surgical examination followed with bipolar coagulation hemostasis under general anesthesia. No patient treated with tosillectomy. Conclusions: STH is now a rare condition, the causes of which in child are more or less different from adult.This emergency can be treated in time if a detailed management plan for pediatric STH is formulated.

Cytidine deaminase in human white blood cells has three electrophoretic phenotypes representing the homozygous and heterozygous expression of two common alleles, CDA1 and CDA2, at an autosomal locus. To explain the multibanded pattern of the heterozygote, the enzyme is assumed to have a tetrameric structure.

Acid alpha-glucosidase from the placenta was electrophoretically surveyed in a total of 633 Malaysians, 236 of Malay, 261 of Chinese and 136 of Indian ancestries. A new variant, alpha-glucosidase 3-1 was observed in 1 Malay and 3 Indians. A polymorphism for this enzyme was observed among Indians, but in Chinese and Malays variants are rare. Phenotype 2-1 was observed once in a Chinese and once in a Malay.

The polymorphism of Gc (group-specific components) has been investigated for a series of 3,160 individual samples from 11 Mongoloid populations in Asia and North and South America by isoelectric focusing on polyacrylamide gels. The samples fall into six Gc phenotypes which can be explained by the three common alleles, Gc1F, Gc1S, and Gc2, together with several variant phenotypes explained as the heterozygotes for the three common alleles. The distribution of Gc1F suballele appears to be considerably different from population to population among Mongoloids, ranging from 0.105 (Machiguenga Indians, Peru) to 0.609 (Kadazan, Borneo). A clear geographic cline from Southeast Asia into South America in Gc1F allele was observed in the populations. In general, Gc1F allele frequencies are lower in European populations and higher in African populations. The range of variability in the Gc1F values observed among the Asiatic populations is between the Africans and the Europeans.

A rare electrophoretic variant of superoxide dismutase (SOD) was found in one Filipino of 146 Filipinos, 1382 Malaysians and 816 Indonesians examined. The variant consists of two usual bands and two slower migrating bands similar to those reported earlier. Superoxide dismutase variants are common among people of certain localized regions in Europe, however, this is the first report of such a variant occurring in people of non-European origin.