RESUMEN
Background@#The ichthyosis is a hereditary skin disease and inherited by autosomal dominant, autosomal recessive and X recessive trait separately. The X-linked ichthyosis (XLI) is the most frequent cutaneous disease and general incidence accounts for one in 2000-5000 male births. Molecular pathogenesis of XLI is due to mutations, which are large deletion, missense, frame shift and nonsense in STS gene. The vast majority of mutation frequency is a large deletion, which are found in 85-90% of patients with XLI. An exon deletion of the STS can be detected by Polymerase chain reaction with exon specific primers. An identification of STS gene mutation has various importance such as 1) detection of mutation type; 2) for genetic counselling, 3) disease severity, 4) carrier detection.@*Methods@#In the present study, pedigree analysis was used for type of inheritance, and Polymerase chain reaction was used to detect a deletion in STS gene and normal control used. A deletion was identified in case PCR bands were not visualized in agarose gels. @*Results@#We included one patient, who had typical symptoms of XLI including dark, adherent scales on skin. Mutation analysis of the STS gene showed that the patient had whole gene deletion (del: Exon 1-10), which was demonstrated by the repeated amplification failure of exons. We used a sample of healthy man as a wild type control, which showed normal amplification of STS gene’s exons. Further, the current study will be focused on the screening of heterozygote large deletion of Del: Exon1-10 of STS gene among patient’s female relatives.@*Conclusion@#An ichthyosis case enrolled in this study was inherited by X-recessive and we identified whole exon deletion of STS gene in this patient.
RESUMEN
@#BACKGROUND. Hemophilia B is X-linked recessive genetic disorder, caused by missing or defective factor IX that results in bleeding longer after an injury or surgery, easy bruising, and an increased risk of bleeding inside joints or the brain. The disorder affects approximately one in 30 000 males worldwide and 18 cases were registered in Mongolia according to statistics of Hemophillia Federation of Mongolia. The annual cost of episodic treatment of an adult with severe hemophilia estimated at ≈53000 USD owing to high cost of treatment developing countries has been adopted to prevent and to forecast the risk of inhibitor. Materials and Methods: The objective of this research is to determine F9 mutations in patients with Hemophillia B in Mongolian population and to assess correlation between genotype and phenotype of disease. Characterization of mutations was performed by direct sequencing of genomic DNA using a Sanger sequencing method. Briefly, the exon or part of the exon deletion was checked and amplified by polymerase chain reaction (PCR). Results: We identified four point mutations and one deletion. No large exon deletion was found in PCR amplification result. As expected, the most common mutations responsible for the disease were point mutations. In general, this study revealed 5 different mutations in unrelated 7 proband and there is good correlation between the type of mutation (location in the amino acid position and domain in the protein) and their functional outcome, yielding a predictable clinical severity.