ABSTRACT
This study aimed to assess mutations in GJB2 gene (connexin 26), as well as A1555G mitochondrial mutation in both the patients with profound genetic nonsyndromic hearing loss and healthy controls. Ninety-five patients with profound hearing loss (>90 dB) and 67 healthy controls were included. All patients had genetic nonsyndromic hearing loss. Molecular analyses were performed for connexin 26 (35delG, M34T, L90P, R184P, delE120, 167delT, 235delC and IVS1+1 A-->G) mutations, and for mitochondrial A1555G mutation. Twenty-two connexin 26 mutations were found in 14.7% of the patients, which were 35delG, R184P, del120E and IVS1+1 A-->G. Mitochondrial A1555G mutation was not encountered. The most common GJB2 gene mutation was 35delG, which was followed by del120E, IVS1+1 A-->G and R184P, and 14.3% of the patients segregated with DFNB1. In consanguineous marriages, the most common mutation was 35delG. The carrier frequency for 35delG mutation was 1.4% in the controls. 35delG and del120E populations, seems the most common connexin 26 mutations that cause genetic nonsyndromic hearing loss in this country. Nonsyndromic hearing loss mostly shows DFNB1 form of segregation.
Subject(s)
Connexins/genetics , Deafness/genetics , Adolescent , Adult , Case-Control Studies , Child , Child, Preschool , Connexin 26 , DNA, Mitochondrial/genetics , Female , Gene Frequency , Genes, Mitochondrial , Heterozygote , Humans , Infant , Male , Middle Aged , MutationABSTRACT
A common polymorphism of the FXIIIA gene, which is characterized by a Val --> Leu exchange at amino acid position 34 (FXIII Val34Leu), was studied in this case-control study. The authors sought to determine whether there was an association between this polymorphism and pediatric stroke. The case-control study included 116 patients with cerebral infarct who were younger than 18 years. All were clinically diagnosed, and the infarction was verified with cranial imaging of the brain. The data revealed that the FXIII gene Val34Leu polymorphism was not associated independently with pediatric stroke in the population and that it does not have any effect in PT 20210A carriers. However, although the difference was not significant, the risk of thrombosis decreased 2-fold to the protective side in patients carrying FV1691A. This may be an important clue and needs further study in FV1691A carriers with and without thrombosis.
Subject(s)
Cerebral Infarction/genetics , Factor XIII/genetics , Leucine/genetics , Polymorphism, Genetic/genetics , Valine/genetics , Adolescent , Child , Child, Preschool , DNA Mutational Analysis , Female , Humans , Infant , Male , Turkey/epidemiologyABSTRACT
Platelet-dependent thromboembolism is an underlying mechanism in the pathogenesis of stroke. 5-HT2A receptor gene is expressed in human platelet, coronary artery (blood vessels) and brain. A polymorphism T102C at the 5-HT2A receptor gene was found that may possibly affect the 5-HT2A receptor function. As there is no existing data on T102C variant of 5-HT2A receptor gene in pediatric stroke, we aimed to study in this case-control study whether there is a association between this polymorphism and pediatric stroke. 111 patients (10 months-18 years old) with cerebral infarct and 79 healthy control was included to our study. Polymerase chain reaction (PCR) of the T102C alteration at the 5-HT 2A receptor gene was performed. Our data revealed that, 5-HT (2A) receptor T102C polymo phism was not associated with pediatric stroke in our population either alone or in combination with underlying pro thrombotic factors. However, this needs to be clarified with further studies.
