OBJECTIVETo establish a method of multiplex ligation-dependent probe amplification (MLPA) for clinical screening of Williams syndrome (WS) and for routine use in WS diagnosis.

METHODSProbes for MLPA were designed according to the frequent deletion regions, and used to screen the two patients suspected with Williams syndrome, and the density of the bands were analyzed with software. Linkage analysis using polymorphic markers was performed to confirm the positive result of MLPA.

RESULTSThe MLPA data indicated that the two children had possible microdeletions in the WS critical region. The deletions were confirmed and both were maternal origin by polymorphism analysis.

CONCLUSIONMLPA is a quick and convenient method for detecting deletion or duplication mutations. It can provide reliable and helpful information for clinical diagnose of Williams syndrome.