The Application Of Detecting LDL-R Function In The Diagnosis Of Familial Hypercholesterolemia

ObjectiveFamilial hypercholesterolemia(FH) is an inherited autosomal dominant disorder of lipoprotein metabolism caused by mutations in the LDL-R gene. It was reported that 5-10% premature coronary artery disease(CAD) were casued by FH. Therefore early diagnosis of FH is very important to prevention and cure of CAD. The objective of our study was to discuss the role of detecting LDL-R function in the Diagnosis of FH, and to establish a foundation for founding an approach about early diagnosis of FH.MethodsFirst ,we established a method of detecting LDL-R function in B lymphocyte, which was on the base of Two Colour Fluorescence Flow Cytometry. Then,30 possible FH were selected as experimental group and 20 normal people as normal control. All the people were collected the result of physical examination,blood lipid test,genetics investigation and so on. With established method, we detected LDL-R function in B lymphocyte of these people and found these people whose LDL-R function in B lymphocyte were not normal. According to the difference on LDL-R function,we decided the abnormal functional domain which was caused by LDL-R gene mutation. The LDL-R gene of 4 people which had the same abnormal functional domain(NO.6,NO.7,NO.17,NO.25 in experimental group)were analyzed with nucleotide sequence analytical technique in order to make a final diagnosis of FH.ResultFirst, the method of detecting LDL-R function in B lymphocyte had established successfully. Optimization concentration of DIL-LDL was 1ul antibody in 100ul cell suspension, and optimization reaction time was 1 hour. 30 possible FH were detected LDL-R function in B lymphocyte, LDL-R function in B lymphocyte of some people were abnormal. With this method, we made a final dignosis of some people in experimental group as FH. NO.6 was a compound heterozygosis mutation in the extron 4 and 12of LDL-R gene; NO.7 was a heterozygosis mutation in the extron 4 of LDL-R gene; NO.17 was a heterozygosis mutation in the extron 12 of LDL-R gene; NO.25 was a homozygosis mutation in the extron 13 of LDL-R gene.ConclusionThe established method of detecting LDL-R function in B lymphocyte played a role of screening initially in the diagnosis of FH, the study established a foundation for founding an approach about early diagnosis of FH.