Background: Monostotic Fibrous Dysplasia (MFD) is thought to be caused by somatic mosaic activating mutations in GNAS. However, previous GNAS mutation analyses of MFD patients using direct sequencing of bone samples detected activating GNAS mutations only in 21 of 40 cases (52.5%) (Hum Pathol 2012; 43: 1234). We reported that next generation sequencing (NGS) detected somatic activating GNAS mutations sensitively from peripheral blood samples in McCune-Albright syndrome (PLoS One 2013; 8: e60525).
Objective and hypotheses: To determine if we could detect somatic activating GNAS mutations in MFD patients using direct sequencing of bone samples and NGS of peripheral blood samples.
Method: The study included eight patients with MFD who underwent operation at our institution. We performed direct sequencing of bone samples and NGS of blood samples from all patients.
Results: We detected somatic activating GNAS mutations in all patients by direct sequencing of bone samples and/or by NGS of blood samples (Table 1).
|Patients||Age (years)||Sex||PCR amplification using bone sample||Detection of GNAS mutations|
|Material||GNAS||GAPDH||DS-bone||NGS-blood||Type of mutation|
|DS: direct sequencing, FFPE: formalin fixed paraffin embedded sample. ND: not done.|
|1Previous repeated operations caused severe bone calcification.|
Conclusion: This result indicates that MFD is a single disorder caused by somatic mosaic activating mutations in GNAS. Formic acid used for decalcification might cause DNA degradation in case 1, 2 and 5.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology