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.


CONCLUSIONS
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.
Zhang
Yu-zhou
YZ
Ruijin Hospital, Shanghai Second Medical University, Shanghai, 200025 PR China.
Sun
Shun-chang
SC
Wu
Hua-cheng
HC
Fan
Qi-shi
QS
Song
Yong-jian
YJ
Yu
Wen
W
Jeanpierre
Marc
M
Urtizberea
J Andoni
JA
D044466:Asian People / Q000235:genetics; D015139:Blotting, Southern; D002681:China; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D020391:Muscular Dystrophy, Facioscapulohumeral / Q000208:ethnology / Q000235:genetics*; D010375:Pedigree; D011110:Polymorphism, Genetic; D020080:Tandem Repeat Sequences / Q000235:genetics*