[The linkage disequilibrium of four loci in hepatic lipase promoter gene of cerebral infarction patients in Shanghai].

OBJECTIVE: To investigate the single nucleotide polymorphism (SNP), the distribution of their haplotypes and linkage disequilibrium of hepatic lipase (HL) gene promoter 250G/A, 514C/T, 710T/C and 763A/G in cerebral infarction patients of Shanghai. METHODS: Peripheral blood sample were collected from 133 patients with cerebral infarction and 112 healthy controls in Shanghai. The HL gene polymorphism was analyzed by polymerase chain reaction- restriction fragment length polymorphism. RESULTS: There were statistically significant differences in genotype and allele frequencies between the healthy controls and the patients with cerebral infarction in -250G/A and -514C/T genotypes and allele frequencies (all P < 0.05). However, there were no significant differences in genotype and allele frequencies in -710T/C and -763A/G between the healthy controls and the patients with cerebral infarction (all P > 0.05). Besides, there was a strong linkage disequilibrium between -250G/A and -514C/T, -710T/C, and -763A/G respectively, between -514C/T and -710T/C and -763A/G respectively, and between -710T/C and -763A/G. When the haplotypes were -250G/-514C, -250G/-710C, -250G/-763G, -514C/-710C, and 514C/-763G respectively, the frequencies in the cerebral infarction group were significantly lower than that in the healthy controls. When the haplotype was -250A/-514T, -250A/-710T, -250A/-710C, -250A/-763G, -514T/-710C, -514T/-763G, and -710T/-763G respectively, the frequencies in the cerebral infarction group were significantly higher than those in the healthy controls. CONCLUSION: There are significant haplotypes and linkage disequilibrium among the four SNPs of HL gene in the cerebral infarction patients of Shanghai. The haplotypes GC, GG, and CC lower the incidence rate of cerebral infarction, while the haplotypes AT, AC, AG, TC, and TG increase the incidence rate of cerebral infarction.

Polymorphism of the D4Z4 locus associated with facioscapulohumeral muscular dystrophy 1A in Shanghai population.

OBJECTIVE: To investigate the D4Z4 repeats on chromosome 4q35 in normal individuals in Shanghai and analysis the polymorphism of the D4Z4 locus. METHODS: The length of D4Z4 repeats on chromosome 4q35 in 191 normal individuals in Shanghai was determined by pulsed-field gel electrophoresis and Southern blotting after double digestion with Eco RI and Bln I. The number of short D4Z4 repeats was counted after partial digestion with Kpn I. RESULTS: Among 191 normal individuals in Shanghai, seventeen showed the size of D4Z4 fragments ranged from 22 to 34 kb, i.e. 8.9% of individuals had fewer numbers of D4Z4 repeats. Of these 17 individuals, sixteen showed the short D4Z4 fragment on chromosome 4q35, and one low D4Z4 fragment was correlated to 4q35--> 10q26 translocation. CONCLUSION: The frequency of individuals having fewer numbers of D4Z4 repeats on chromosome 4q35 in Shanghai population is higher than that in Caucasian population although the short D4Z4 fragment on chromosome 4q35 is associated with facioscapulohumeral muscular dystrophy. These findings suggest that other factors may also contribute to facioscapulohumeral muscular dystrophy.