Contributions
Abstract: PB2497
Type: Publication Only
Background
Thalassemia is one of the most pervasive monogenic diseases worldwide. In China, southern provinces were known as high incidence areas of thalassemia. But thalassemia is now becoming increasingly common in northern China because of continued migration.
Aims
We compared gene spectrum of α and β-thalassemia in northern and southern China, and compared our data in provinces of different elevations. The results may help to understand the similarities and differences of people who reside in the north China but originate from different areas.
Methods
Positive patients or carriers were analyzed from 2136 suspected α and β-thalassemia carriers who were referred to Peking Union Medical College Hospital from 2012 to 2017 for diagnosis. Gap-PCR and RDB (reverse dot blot) analysis were applied for detections of common α and β-thalassemia gene mutations. Basic clinical data from these patients or carriers were collected. Telephone follow-up survey was conducted on their ancestral information, to confirm whether these northerners have southern lineage.
Results
A total of 1059 carriers (male 299, female 760, age range from 0 to 82 years, mean age 30.2 years) were selected from north dweller, 183 (17.3%) of them with pure northern descent in three generations and the rest 876 (82.7%) carriers with south descent. Most of our people with positive thalassemia gene findings had no or mild symptoms. People who originated from the north origin had higher percentage of β-thalassemia gene mutations compared with people from the south origin (72.8% vs 62.4%, χ2=9.92, P =0.001). Analysis of the individual gene distribution of the south and north did not show significant difference either in α-thalassemia (P=0.221) or β-thalassemia (P=0.979). Differences between gene distributions in provinces with similar average altitudes were relatively small. No significant statistical differences in the frequency of α mutation were found in different altitude levels. But in β thalassemia, the frequency of 6 most common mutations were significantly different in provinces with altitude below 500 meters, about 500-1000 meters, and above 1000 meters (χ2 test, P < 0.05).
Conclusion
Most of people with positive thalassemia gene findings who reside in the north China are thalassemia carriers. People with north lineage may have higher frequency of β mutation than those originated from the south, but they had similar spectrum of α and β mutations. People lived at different level of altitudes may have different spectrum of β mutations.
Session topic: 28. Thalassemias
Keyword(s): mutation analysis, Thalassemia
Abstract: PB2497
Type: Publication Only
Background
Thalassemia is one of the most pervasive monogenic diseases worldwide. In China, southern provinces were known as high incidence areas of thalassemia. But thalassemia is now becoming increasingly common in northern China because of continued migration.
Aims
We compared gene spectrum of α and β-thalassemia in northern and southern China, and compared our data in provinces of different elevations. The results may help to understand the similarities and differences of people who reside in the north China but originate from different areas.
Methods
Positive patients or carriers were analyzed from 2136 suspected α and β-thalassemia carriers who were referred to Peking Union Medical College Hospital from 2012 to 2017 for diagnosis. Gap-PCR and RDB (reverse dot blot) analysis were applied for detections of common α and β-thalassemia gene mutations. Basic clinical data from these patients or carriers were collected. Telephone follow-up survey was conducted on their ancestral information, to confirm whether these northerners have southern lineage.
Results
A total of 1059 carriers (male 299, female 760, age range from 0 to 82 years, mean age 30.2 years) were selected from north dweller, 183 (17.3%) of them with pure northern descent in three generations and the rest 876 (82.7%) carriers with south descent. Most of our people with positive thalassemia gene findings had no or mild symptoms. People who originated from the north origin had higher percentage of β-thalassemia gene mutations compared with people from the south origin (72.8% vs 62.4%, χ2=9.92, P =0.001). Analysis of the individual gene distribution of the south and north did not show significant difference either in α-thalassemia (P=0.221) or β-thalassemia (P=0.979). Differences between gene distributions in provinces with similar average altitudes were relatively small. No significant statistical differences in the frequency of α mutation were found in different altitude levels. But in β thalassemia, the frequency of 6 most common mutations were significantly different in provinces with altitude below 500 meters, about 500-1000 meters, and above 1000 meters (χ2 test, P < 0.05).
Conclusion
Most of people with positive thalassemia gene findings who reside in the north China are thalassemia carriers. People with north lineage may have higher frequency of β mutation than those originated from the south, but they had similar spectrum of α and β mutations. People lived at different level of altitudes may have different spectrum of β mutations.
Session topic: 28. Thalassemias
Keyword(s): mutation analysis, Thalassemia