[Diagnosis of a patient with adjacent gene deletion syndrome with DMD complete deletion type of Duchenne muscular dystrophy].

OBJECTIVE

To identify the etiology of a patient with severe symptoms of DMD and to trace its pathogenic gene, so as to provide a basis for genetic counseling and clinical intervention.

METHODS

Multiple ligation-dependent probe amplification (MLPA) technique was used to analyze exon deletion/repetitive variant of DMD gene, and further analysis was performed by chromosome G-banding, fluorescence in situ hybridization (FISH) and SNP array analysis.

RESULTS

The MLPA results of the proband showed that the exon 1-79 of DMD gene were deleted, the G-banding karyotype of blood sample was 46, XY, and the deletion of the short arm of X chromosome was found by FISH. SNP array results showed that 5.8Mb (29 628 158-35 434 714) deletion occurred in the Xp21.2p21.1 region of X chromosome, and the patient was diagnosed as the contiguous deletion syndrome involving the genes of IL1RAPL, MAGEB1-4, ROB, CXorf2, GM, AP3K7IP, FTHL1, DMD, FAM47A, TMEM47, and FAM47B.

CONCLUSION

The exact pathogenic site of this family is the deletion of 5.8 Mb (29 628 158-35 434 714) in the Xp21.2p21.1 region of X chromosome, which can be used for prenatal diagnosis. High resolution SNP array technique plays an important role in detecting potential chromosome abnormalities in patients.