RESUMO
To select polymorphic short tandem repeat markers within X-linked nuclear protein (XNP) gene, genomic clones which contain XNP gene were recognized by homologous analysis with XNP cDNA. By comparing the cDNA with genomic DNA, non-exonic sequences were identified, and short tandem repeats were selected from non-exonic sequences by using BCM search Launcher. Polymorphisms of the short tandem repeats in Chinese population were evaluated by PCR amplification and PAGE. Five short tandem repeats were identified from XNP gene, two of which were polymorphic. Four and 11 alleles were observed in Chinese population for XNPSTR1 and XNPSTR4, respectively. Heterozygosities were 47% for XNPSTR1 and 70% for XNPSTR4. XNPSTR1 and XNPSTR4 localized within 3' end and intron 10, respectively. Two polymorphic short tandem repeats have been identified within XNP gene and will be useful for linkage analysis and gene diagnosis of XNP gene.
Assuntos
DNA Helicases , Proteínas Nucleares/genética , Polimorfismo Genético , Sequências de Repetição em Tandem , Mapeamento Cromossômico , Humanos , Proteína Nuclear Ligada ao XRESUMO
OBJECTIVE: To evaluate the role of homozygosity mapping in the fine mapping of the genes responsible for the rare autosomal recessive diseases. METHODS: Polymerase chain reaction-single sequence length polymorphism was used to genotype the family members from 8 families with osteoporosis-pseudoglioma syndrome(OPS) for 14 polymorphic loci within candidate region. The OPS candidate region was narrowed by searching for homozygous region in affected. RESULTS: The OPS candidate region was narrowed to a 1 cM interval between D11S1296 and D11S4136. CONCLUSION: Homozygosity mapping is a powerful method for mapping and narrowing the candidate region of the genes responsible for the rare autosomal recessive diseases.