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Biomedical subjects

I A Shagina

Publications and source records attributed to I A Shagina.

5 recordsLinked to original sources
PubMed2006

[Genetic screening among children with congenital and early childhood hearing loss].

Prevalence of mutations of genes of connexin 26, connexin 30 and mitochondrial DNA was studied among children with congenital and early childhood hearing loss. Screening with available methods of DNA diagnosis was conducted in some specialized schools. It was found that genetic disorders among children with congenital and early childhood hearing loss are rather frequent. Genetic consulting of parents with normal hearing carrying abnormal gene can help avoid birth of deaf children.

Age Factors↗
PubMed2002

[DNA diagnosis in congenital and early childhood hypoacusis and deafness].

Congenital deafness affects 0.05-0.1% children. 90% of them were born from parents with normal hearing. There were no hearing defects in their families. In 70% of deafness cases deafness is the only symptom of the disease and is thought to be non-syndromal. Hypoacusis of unclear etiology may be congenital in 50% cases. Half of cases of severe autosomic-recessive non-syndromal hypoacusis (deafness) appear because of changes in only one gene--gene of connexine-26. Two thirds of the defects in this gene arise because of one mutation--35delG. Mean rate of this mutation carriage in Russia is over 2%. Identification of mutation 35delG in gene Cx26 is performed with the use of polymerase chain reaction. Genetic examination of 75 children with isolated hypoacusis (deafness) has detected deletion 35delG in both gene copies in 23 children (30%). 10 patients (13.4%) had mutation 35delG only in one copy of gene Cx26. Hearing defects in the latter may be related with the presence of another mutation in the same gene. A total of 33 patients (42%) carried deletion 35delG. According to our findings, the changed genotype is characterized primarily by bilateral neurosensory hypoacusis of the third-fourth degree. Weaker loss of hearing is rare. Thus, mutations in connexine gene26 present a problem for parents with normal hearing. Therefore, families with a deaf child should be referred for medicogenetic consultations.

Child↗
PubMed2001

[Sensorimotor neuropathy with X-linked dominant inheritance].

Familial sensomotor neuropathy (FSMNX1) is reported to contribute significantly to FSMN spectrum. FSMNX1 is referred to FSMN type I but in respect to several signs is regarded as an intermediate one between type I and type II. A family including 26 patients in 5 generations has been described, 14 patients being examined in the study. Molecular genetic investigation showed that the disease was determined by mutation in connecsin gene 32 (Cx32). The mutation described is represented by a single nucleotide substitution 68T > C in codon 23 (GTA > GCA). A large proportion of presubclinical cases, preferentially in women, have been found in the family, that is in line with a type of inheritance. Substantial interfamilial disease polymorphism, especially by an age of onset, and symptoms rare for FSMN have been showed as well. Literature data on clinical genealogical, electrophysiological and molecular-genetic characteristics of FSMNX1 are analyzed comparing with own observations. Practical aspects of FSMNX1 diagnosis using DNA are discussed.

Adult↗
PubMedDate not supplied

[A method for the preparation of normalized cDNA libraries enriched with full-length sequences].

We developed a new method for the preparation of normalized cDNA libraries enriched with full-length sequences. It is based on the properties of the recently characterized duplex-specific nuclease from the hepatopancreas of the Kamchatka crab. The duplex-specific nuclease is thermostable, it effectively cleaves double-stranded DNA and is inactive toward single-stranded DNA (Shagin et al., Genome Res., 2002, vol. 12, pp. 1935-1942). Our method enables the normalization of cDNA samples enriched with full-length sequences without use of laborious and ineffective stages of physical separation. The efficiency of the method was demonstrated in model experiments using cDNA samples from several human tissues.

Animals↗