[Detection of deletional determinants of alpha-thalassemia in Li people in Hainan province by a single tube multiplex polymerase chain reaction method].

OBJECTIVE: To develop a single tube multiplex polymerase chain reaction technique (mPCR) and use it to screen 3 deletional alpha-globin genes, namely -alpha(3.7), -alpha(4.2) (single gene deletion), and --SEA (South East Asia double gene deletion) in the Li people in Hainan province. METHODS: Based on previously developed 3 separate PCR methods used to detect the -alpha(3.7), -alpha(4.2), --SEA respectively, a single tube mPCR was investigated, optimized, and used to detect the genotypes of 40 samples from well-known alpha-thalassemia patients and 116 non-relative individuals of Li nationality in Hainan province. RESULTS: The results of the 40 samples detected by mPCR were the same as those by the 3 separate PCR Methods. Among the 116 sample, the combined incidence of -alpha(3.7) and -alpha(4.2) was found to be as high as 38.0%, and the -alpha(4.2) genotype was more frequent than the -alpha(3.7) genotype in the Li people. No --(SEA) deletion was found in the Li people. CONCLUSION: The mPCR technique shows a good sensitivity and specificity. The Hainan Li people has the highest incidence of -alpha(3.7) and -alpha(4.2) among Chinese.

Detection of three common, deletional alpha-thalassemia determinants in Southern China by a single-tube multiplex polymerase chain reaction method.

alpha-Thalassemia (thal) is one of the most common inherited disorders in the world and in Southern China. Three large deletions of the alpha-globin gene, namely the -alpha3.7 and -alpha4.2 (single gene deletions), and --SEA (Southeast Asian double gene deletion), are the main alpha-thal abnormalities in Southern China. We have developed a reliable, single-tube multiplex polymerase chain reaction (m-PCR) assay for these three most frequently observed determinants in Southern China. By using this assay, we detected 40 alpha-thal patients from Guangdong, Guangxi Province, and analyzed 116 blood samples from the Li ethnic group of Hainan Province. To our surprise, the combined incidence of -alpha3.7 and -alpha4.2 was found to be as high as 38.0% among the Li people, and the -alpha4.2 genotype is more frequent than -alpha3.7 in the Li people. No SEA deletions were found in the Li samples.

[Y-chromosome-specific microsatellite variation in Li ethnic groups of Hainan Island, China].

OBJECTIVE: The study was conducted to reveal the distribution of genetic polymorphism of four Y chromosome specific short tandem repeat (Y-specific STR) loci in Li ethnic groups in Hainan Island, China. METHODS: Four tetranucleotide STR loci were simultaneously amplified with fluorescently labeled primers, and genotypes were determined with an automated DNA sequencer. RESULTS: Among 230 unrelated males, the alleles at the four Y-specific STR loci were composed of some complex repeat structure. 4,5,4,5 alleles were observed in loci DYS3891, DYS390, DYS391, DYS393 respectively. A set of human allele ladders for the typing of the four Y-specific STRs was obtained in Li ethnic population. Gene diversity index (D) and haplotype diversity data were estimated for the four Y-STRs. CONCLUSION: The preliminary study indicates a reference population for detecting male migration events and should be useful in population genetics and forensic applications.

[Polymorphism analysis for DYS19 and DYS287 of three Li populations in Haina Island, China].

The distribution of Y-chromosome specific microsatellite DYS19, in 289 males of three ethnic populations in Hainan Island was studied with the method of PCR followed by denatured polyacrylamide gel electrophoresis and silver staining. The three ethnic populations are Bendi Li, Qi Li and Ha Li. The results showed that four alleles (190bp, 194bp, 198bp, 202bp designated as alleles B, C, D and E respectively), were observed in DYS19, the frequency ranged from 0.660-0.854, and was predominant in three Li subgroups. The pairwise comparison with Fisher's Exact test reveals that there exists significant difference (P<0.01) in DYS19 phenotype distribution between Qi Li and Ha Li populations. The polymorphism of the Y-chromosome specific Alu insert sequence DYS287 was investigated also in three Li populations. The results demonstrated that with 150 bp product in all Bendi-Li, Qi-li and Ha-li, YAP element is absent. The preliminary study provides reference populations for detecting male migration events and for reconstructing paternal history.