Abstract: Objective：To develop a reliable and exact protocol for the multiple displacement amplification (MDA)-based preimplantation genetic diagnosis (PGD) of X-linked chronic granulomatous disease (X-CGD). Methods：The haplotype analysis of X-CGD was performed for 16 short tandem repeats (STR) loci on both sides of the CYBB gene. Whole-genome amplification of single cell was carried out by MDA. The STR loci with polymorphism as demonstrated by the linkage analysis and the specific amplification of CYBB gene were analyzed. The locus Amel was used for sex determination. Results：Seven STR loci were found to be polymorphic in the linkage analysis. MDA was performed in 10 single lymphocytes and 10 single blastomeres. The efficiencies of PCR amplification of the pathogenic CYBB exon 8 was 100%. ADO of the mutant allele of CYBB was detected in one of the lymphocytes, the ADO rate 10% (1/10). For those single blastomeres, the 215 bp band corresponding to the normal allele was detected in all MDA products, while the abnormal 204 bp band was not detected. For the 7 polymorphic STR loci and AMELs, the PCR amplification efficiency and the ADO rate were 96.9% (155/160) and 11.3% (13/115), respectively. Conclusions：In this study, MDA combined with pathogenic gene specific amplification and haplotype analysis was performed to detect chronic granulomatous disease in a single cell level. The combination of the two techniques can improve the efficiency of PGD for CGD by reducing the misdiagnosis caused by contamination and ADO.

Key words: X-linked chronic granulomatous disease, Pedigree, Preimplantation diagnosis, Multiple displacement amplification, Haplotype analysishaplotype analysis