Similarity of DMD gene deletion and duplication in the Chinese patients compared to global populations

Xiaozhu Wang^*¹^,2 , Zheng Wang^*³ , Ming Yan¹^,2 , Shangzhi Huang³ , Tian-Jian Chen¹^,5 and Nanbert Zhong¹^,2^,4

¹Peking University Center of Medical Genetics, Peking University, Beijing, China

²Department of Medical Genetics, Peking University Health Science Center, Peking University, Beijing, China

³Department of Medical Genetics, Peking Union Medical College/Institute of Medical Sciences, Chinese Academy of Medical Sciences, Beijing, China

⁴Department of Human Genetics, New York State Institute for Basic Research in Development Disabilities, Staten Island, New York, USA

⁵Department of Medical Genetics, University of South Alabama, Mobile, Alabama, USA

author email corresponding author email* Contributed equally

Behavioral and Brain Functions 2008, 4:20doi:10.1186/1744-9081-4-20


Published:	29 April 2008

Abstract

Background

DNA deletion and duplication were determined as the major mutation underlying Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD).

Method

Applying multiplex ligation-dependent probe amplification (MLPA), we have analyzed 179 unrelated DMD/BMD subjects from northern China.

Results

Seventy-three percent of the subjects were found having a deletion (66.25%) or duplication (6.25%). Exons 51–52 were detected as the most common fragment deleted in single-exon deletion, and the region of exons 45–50 was the most common exons deleted in multi-exon deletions. About 90% of DMD/BMD cases carry a small size deletion that involves 10 exons or less, 26.67% of which carry a single-exon deletion. Most of the smaller deletions resulted in an out-of-frame mutation. The most common exons deleted were determined to be between exon 48 and exon 52, with exon 50 was the model allele. Verifying single-exon deletion, one sample with a deletion of exon 53 that was initially observed from MLPA showed that there was a single base deletion that abolished the ligation site in MLPA. Confirmation of single-exon deletion is recommended to exclude single base deletion or mutation at the MLPA ligation site.

Conclusion

The frequency of deletion and duplication in northern China is similar to global ethnic populations.