OBJECTIVEPrader-Willi syndrome (PWS) is an example of a human genetic disorder that involves imprinting genes on the proximal long arm of chromosome 15 and SNRPN gene as a candidate gene for this syndrome. The purpose of this study was to show the molecular genetic defects and genomic imprinting basis in Chinese PWS patients and to evaluate the clinical applications of a differential diagnostic test for PWS.

METHODSFluorescence in situ hybridization (FISH) and methylation-specific PCR (MSPCR) techniques were applied for 4 clinically suspected PWS patients. Using three probes, including SNRPN probe for identification of the critical locus in PWS region, D15Z1 and PML control probes for identification of the 15p arm and 15q arm, the authors detected the deletions 15q in PWS. MSPCR was based on sodium bisulfite treatment of DNA and PCR primers specific for the maternal and paternal allele.

RESULTSWhen hybridized with mixed probes, it was found in 2 patients that the central specific signal was absent, but both the flanking control signals were retained, indicating SNRPN gene deletion of chromosome 15q11-13. Bisulfite-modified DNA from all PWS children amplified with methylated allele-specific primer pair showed only maternal 131bp PCR product, indicating the maternal uniparental disomy (UPD15).

CONCLUSIONGenomic imprinting plays an important role in the molecular pathogenesis of PWS that caused by paternal microdeletions of 15q11-q13 or maternal UPD of chromosome 15. The basic defect seemed to be an absence of function of PWS genes that are normally expressed only from the paternal chromosome 15. MSPCR is a rapid and simple PCR-based assay compared with other cyto-molecular tests and its results were consistent with the clinical diagnosis of PWS, so it seems to be a reliable diagnostic method for PWS patients who show abnormal methylation at SNRPN. The genetic differential tests for PWS are important in determining familial recurrence risk.

Adolescent ; Autoantigens ; Chromosome Deletion ; Chromosomes, Human, Pair 15 ; genetics ; Gene Deletion ; Genomic Imprinting ; genetics ; Humans ; In Situ Hybridization, Fluorescence ; Male ; Polymerase Chain Reaction ; methods ; Prader-Willi Syndrome ; genetics ; Ribonucleoproteins, Small Nuclear ; genetics ; snRNP Core Proteins

Adolescent ; Body Height ; Chromosomes, Human, X ; Female ; Growth Hormone ; deficiency ; Humans ; Karyotyping ; Monosomy ; Mosaicism ; Turner Syndrome ; genetics ; metabolism ; pathology

OBJECTIVETo determine the incidence and risk factors on HIV infection among injection drug users (IDU) in Dehong prefecture area of Yunnan province.

METHODSAn epidemiological cohort of HIV-negative IDU had been developed and followed since October, 2004. HIV new infections and related behaviors had been investigated every six months.

RESULTSBy the end of 2008, 760 HIV-negative IDU had been recruited and followed for a total of 1153.6 person-years. 47 new HIV infections were identified, with an overall incidence of 4.07/100 person-years during the follow-up period. The HIV incidence was 4.45/100 person-years during 2004 - 2006, 4.50/100 person-years in 2007 and 2.54/100 person-years in 2008. Both the behavior of drug injection and the HIV incidence among the cohort had substantially decreased during the follow-up period. Multiple regression analysis using Cox proportional hazard model indicated that people with Jing-po ethnicity (Hazard ratio, HR = 2.56, 95%CI: 1.06 - 6.19) and other minorities except for Dai (HR = 3.26, 95%CI: 0.89 - 11.96) were at higher risk for HIV infection than the people with Han ethnicity. People injecting drugs with (HR = 2.27, 95%CI: 0.98 - 5.25) or without (HR = 5.27, 95%CI: 2.25 - 12.34) needle sharing were at higher risk for HIV infection than those reporting having no drug injection behavior during the follow-up period.

CONCLUSIONBoth the behavior of drug injection and the HIV incidence among former IDU in Dehong prefecture area of Yunnan province had been decreasing during the four years. However, needle sharing remained the most important risk factor for HIV new infection among IDUs. IDUs with different ethnicities seemed to have different risks towards HIV infection.

Adult ; China ; epidemiology ; Cohort Studies ; Female ; HIV Infections ; epidemiology ; Humans ; Incidence ; Male ; Minority Groups ; Needle Sharing ; Risk Factors ; Substance Abuse, Intravenous ; epidemiology

OBJECTIVETo study the HIV incidence and risk factors among sero-negative spouses of HIV patients in Dehong prefecture of Yunnan province.

METHODSA cohort of sero-negative spouses of the HIV patients had been developed and followed up since November, 2005. HIV new infections and related behaviors had been investigated every six months.

RESULTSBy the end of June, 2008, 790 sero-negative spouses of HIV patients had been recruited, of whom 702 were followed-up for at least one time. During the total 1202.35 person-years, 31 new HIV infections were identified, with an overall incidence of 2.58/100 person-years. The HIV incidence rates were 2.22/100 person-years in 2006, 2.95/100 person-years in 2007 and 2.74/100 person-years in 2008. Data from the Cox proportional hazard regression model indicated that those who resided in Yingjiang county [hazard ratio (HR) = 4.37, 95%CI: 1.48 - 12.90, P = 0.008], ever using drugs (HR = 3.49, 95%CI: 1.09 - 11.18, P = 0.035), or having an HIV-infected spouse who never exposed to antiretroviral treatment (HR = 3.60, 95%CI: 1.41 - 9.16, P = 0.007) were at higher risk for HIV infection.

CONCLUSIONSero-negative spouses of HIV patients in Dehong prefecture of Yunnan province had a relatively high incidence of HIV new infection during 2006-2008. More efforts should put on those people living in these areas, having a history of drug use or having an HIV-infected spouse who had never been exposed to antiretroviral treatment.

Adolescent ; Adult ; China ; epidemiology ; Female ; HIV Infections ; epidemiology ; HIV Seronegativity ; Humans ; Incidence ; Male ; Middle Aged ; Prospective Studies ; Risk Factors ; Sexual Behavior ; Spouses ; Young Adult

Objective To study the HIV incidence and risk factors among sero-negative spouses of HIV patients in Dehong prefecture of Yunnan province. Methods A cohort of sero-negative spouses of the HIV patients had been developed and followed up since November, 2005.HIV new infections and related behaviors had been investigated every six months. Results By the end of June, 2008, 790 sero-negative spouses of HIV patients had been recruited, of whom 702 were followed-up for at least one time. During the total 1202.35 person-years, 31 new HIV infections were identified, with an overall incidence of 2.58/100 preson-years. The HIV incidence rates were 2.22/100person-years in 2006, 2.95/100 person-years in 2007 and 2.74/100 person-years in 2008. Data from the Cox proportional hazard regression model indicated that those who resided in Yingjiang county [hazard ratio (HR) =4.37, 95% CI: 1.48-12.90, P=0.008] , ever using drugs (HR=3.49, 95% CI:1.09-11.18, P=0.035) , or having an HIV-infected spouse who never exposed to antiretroviraltreatment (HR=3.60, 95% CI: 1.41-9.16, P=0.007) were at higher risk for HIV infection.Conclusion Sero-negative spouses of HIV patients in Dehong prefecture of Yunnan province had a relatively high incidence of HIV new infection during 2006-2008. More efforts should put on those people living in these areas, having a history of drug use or having an HIV-infected spouse who had never been exposed to antiretroviral treatment.