Funding for this research was provided by:
National Key Research and Development Program of China (2016YFC0901501, 2016YFC0905102)
CAMS Innovation Fund for Medical Sciences (2016-I2M-1-002, 2017-I2M-2-002)
Received: 9 November 2019
Accepted: 23 February 2020
First Online: 2 March 2020
Ethics approval and consent to participate
: This study was approved by the local ethics committee of Peking Union Medical College Hospital. The study was included as a subgroup of National Rare Disease Registry System of China (NRDRS, 2016YFC0901500) [CitationRef removed]. All patients provided written informed consent before entering the NRDRS registry.
: Not applicable.
: The authors declare that they have no competing interests.