[A study on the (CA)n in FVIII gene in Han ethnic group in Guangxi Zhuang Autonomous Region by amplification polymorphisms combined with silver staining].
OBJECTIVE
Hemophilia A is an inherited bleeding disorder caused by defects in factor VIII (FVIII) gene. In the present study, the frequencies of the microsatellite alleles at introns 13 and 22 in the factor VIII gene were analyzed in the group of Han nationality in Guangxi Zhuang Autonomous Region to explore their diagnostic value for hemophilia A. These two sites were also used to detect the carriers in 13 hemophilia A families.


METHODS
Ninty-one individuals of Han ethnic group in Guangxi Zhuang Autonomous Region (135 X chromosomes) and 13 HA families were subjected to molecular studies. First, these two fragments were PCR amplified simultaneously. Then, silver staining was used later to show their polymorphisms. The investigators selected one sample at random to obtain its lengths of the PCR products at these two sites by ABI310 PCR amplifier. After counting its repeated numbers of (CA) according to the documents concerned, the repeated numbers of the other samples could be counted easily.


RESULTS
In the 91 individuals, 6 and 4 alleles were detected at these two sites, respectively. At intron 13 the allele frequencies ranged from 0.0002 to 0.5408 and polymorphism information content (PIC) was 0.5899. At intron 22 the allele frequencies ranged from 0.0444 to 0.4963 and its PIC was 0.5359. The actual heterozygosity for intron 13 and intron 22 were 0.6364 (28/44) and 0.5227 (23/44), respectively. In 13 hemophilia A families with positive history, 9 of them were diagnosed by this method and the diagnosis rate was 69%.


CONCLUSIONS
With high PICs, (CA)n at intron 13 and intron 22 were two valuable sites in the diagnosis of hemophilia A in the population of Han ethnic group in Guangxi Zhuang Autonomous Region. Compared with some other HA restrictive fragment length polymorphisms (RFLP), intron 22 (GT)n (AG)n was more informative.
Zhu
Chun-jiang
CJ
Department of Pediatrics, Guilin Medical College Affiliated Hospital, Guilin 541001, China.
Liu
Jing-zhong
JZ
Ou
Wei-lin
WL
Long
Gui-fang
GF
Liang
Yan
Y
Wang
Zhan-yong
ZY
Zheng
Ming-ci
MC
D000483:Alleles; D054458:Amplified Fragment Length Polymorphism Analysis; D044466:Asian People / Q000235:genetics; D005169:Factor VIII / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006467:Hemophilia A / Q000175:diagnosis / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D007438:Introns; D008297:Male; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D016622:Silver Staining
D005169:Factor VIII