METHODS: During 2012 to 2017, suspected thalassemia people were detected for common α- and β-thalassemia mutations by gap-Polymerase Chain Reaction (PCR) and reverse dot blot (RDB) analysis in Peking Union Medical College Hospital. One thousand and fifty-nine people with thalassemia mutations were analyzed retrospectively. We picked mutated individuals who originally came from northern areas, and conducted telephone follow-up survey in order to collect their ancestral information. Besides, we used "thalassemia", "mutation", and "Southeast Asian countries" as keywords to search the relevant studies in PubMed and Embase databases.
RESULTS: All carriers included in our study were resided in northern China. Among them, 17.3% were native northerners and 82.7% were immigrants from southern China. Although substantial difference was found in α- and β-thalassemia ratio and detailed spectrum of α- and β-globin mutation spectrum between our data and data obtained from a previous meta-analysis literature focused on southern China, the most common gene mutations were the same. Similar β-thalassemia mutation spectrum was found among Thai, Malaysian Chinese, and Guangdong people, however, no other similarities in gene profile were found between Chinese and other ethnic groups in Southeast Asia.
CONCLUSION: Chinese people in different areas had similar gene mutation, whereas they had significantly different mutation spectrums from other ethnic groups in Southeast Asia.
AREAS COVERED: Published and unpublished studies from January 1981 to June 2020 were systematically reviewed on PubMed, Web of Science and Scopus. Additionally, the reference list of all studies was hand-searched for additional studies. This effort identified a total of 104614 registered patients and suggests identification of at least 10590 additional PID patients, mainly from countries located in Asia and Africa. Molecular defects in genes known to cause PID were identified and reported in 13852 (13.2% of all registered) patients.
EXPERT OPINION: Although these data suggest some progress in the identification and documentation of PID patients worldwide, achieving the basic requirement for the global PID burden estimation and registration of undiagnosed patients will require more reinforcement of the progress, involving both improved diagnostic facilities and neonatal screening.
SHORT CONCLUSION: In conclusion, INDELs and VNTRs could have important functional consequences in the pathophysiology of obesity, and research on them should be continued to facilitate obesity prediction, prevention, and treatment.