Application of digital droplet PCR in detection of activating hotspot mutations in GNAS gene in children with McCune-Albright syndrome / 中华内分泌代谢杂志

ABSTRACT

Objective:To detect the known hotspot mutations of GNAS in children with McCune-Albrigtht syndrome(MAS) by droplet digital PCR, and to explore its application value in the diagnosis of MAS.Methods:A total of 122 children with MAS were enrolled in the pediatric department of Ruijin Hospital Affiliated to Medical College of Shanghai Jiaotong University. For the known mutation hotspot of GNAS gene (R201H/C), dd-PCR, real-time fluorescent pyrophosphatic activation polymerase reaction (PAP) and second-generation sequencing were used to detect the presence of gene mutation and to analyse the relevance with the clinical features.Results:GNAS gene mutation was detected in 89 out of 122 children with MAS and 57 cases were found to have mutations. The positive rates of ddPCR, PAP, and second generation sequencing were 77.42%, 29.03%, and 56.25%, respectively. The GNAS gene mutation was detected in all classical triad patients. Among them, the positive rates of ddPCR in peripheral blood of typical and atypical children were 100% and 73.1% respectively, which were significantly higher than those of the other two methods. The detection rate of GNAS mutation in precocious puberty with bone lesions was higher than that in precocious puberty with skin lesions, suggesting that fibrous dysplasia with precocious puberty is an important basis for clinical diagnosis of MAS in children.Conclusion:Precocious puberty is the most common endocrine manifestation of MAS in children. Bone fibrous dysplasia with precocious puberty is an important factor in clinical diagnosis. ddPCR has high sensitivity, which can be helpful for molecular diagnosis of MAS.