 4. Blood specimen collecting and analysis: All children are invited to collect vein blood to analysis. The standard blood analysis protocol includes complete blood count CBC, serum creatinine, urea, and uric acid. Blood samples for CBC analysis are collected using tubes with EDTA-K2 as preservative and are frozen at 4C.Blood samples for serum chemistries analysis are collected using tubes without any preservative. All blood samples are delivered to the First Peoples Hospital of Kashgar area for analysis by automated analyzers. All blood samples are analyzed in 12 hours after collection. Also, we will preserve a blood sample of each child in a -80Crefrigerator for further analysis of etiology which include genetics. 