The Linkage Analysis Between Interdigital Patterns Penotypes And Candidate Gene In Families From Guangxi Zhuang Population

Background:Dermatoglyphy, including fingerprints, interdigital patterns (IDPs), footprints etc., is a specific biological phenotype on the body surface of primates, in which the IDPs is the most representative. The study of dermatoglyphy can be traced back to 1823 when Pukinje did the systemic classification of it. Recently, the correlations between dermatoglyphy and some genetic disorders have been approved, some of which have been applied to prenatal diagnosis. However, the detail genetic model of dermatoglyphy remains unknown. Contradictory results have been found in different dermatoglyphy studies in terms of its size, shape and direction. Therefore, the genetic model of dermatoglyphy has not yet established until recently, despite various hypotheses emerged basing on numerous researches in the past decades. The only acceptable conclusion is that dermatoglyphy may be multi-gene involvement, in which every gene plays limited role.The most significant part of the dermatoglyphy is the IDPs, the area connects the finger and the palm. The palm area between thumb and the index finger is called interdigital area I, and the other areas next to it are area II, III, and IV, successively. Different area was separated by the boundary line formed by different ridges. Interdigital patterns can be arch, loop, whorl and other shapes according to their direction, which show a great diversity among species including human being. Although IDPs seems more diverse and more complicated than other body surface patterns, its analysis is much simple, establishing it as a useful model for dermatoglyphic study. In addition, IDPs is also a typical left-right asymmetric trait, whose establishment of genetic model might be a good example for other left-right asymmetric traits.Objective:To explore the candidate loci of human dermatoglyphy via the linkage study on the SNPs from five loci of the SHFM1 gene in Zhuang families members.Method:1. Using graphite powder to get the IDPs of every studied member.2. Collect oral mucous membrane cells from every individual studied with swab, then extract DNA from the cells. Using SNapShot technique to determine the SNPs of five loci (rs4342522, rs10260320, rs12704872, rs6465533, rs12704870) of the SHFM1 gene.3. Analyze the information of SNPs and dermatoglyphy with Linkage analyzing software to explore the candidate loci of human dermatoglyphy.Result:1. According to the new classification, the most common type of IDPs in the population studied here is"2", whereas the most frequent type of IDPs in previous classification is"only in areaâ…£".2. The most frequent haplotypes of SHFM1 gene are TGGCA, TGGTA, TAATA and TGATT according to phase sofeware analysis; while the most common haplotypes of SHFM1 gene are TGGTA, TGGCA, TGATA and TGACA analyzed by HyploView sofeware, indicating that different software may generate different result.3. Linkage analyses by Lingkage software and Genehunter software reveal that the LOD scores among the five loci are almost 0, indicating that no linkage disequilibrium was found among these loci. However, there was an increasing tendency of LOD toward the upstream of rs10260320 and downstream of rs6465533, implying that the dermatoglyphy related gene loci may be located in the outboard of these two loci.Conclusion:The gene loci associated with IDPs may be at the upstream of rs10260320 and the downstream of rs6465533 on the SHFM1 gene.