To investigate the neonatal genetic carrier rate and genotype composition of thalassemia in Haikou city, and to evaluate the application of using dried blood spot specimens of neonates for population screening of thalassemia.

From January 2016 to December 2016, 25% to 50% of all dried blood spot specimens of registered neonates were collected randomly by mechanical samping method in 30 hospitals of Haikou city everyday.Total of 6 864 samples were primarily analyzed by hemoglobin electrophoresis, and those with positive results were secondarily recalled for venous blood collection and subsequent genotyping tests.Feasibility of using neonatal dried blood spot specimens for population screening of thalassemia was retrospectively analyzed.

A total of 6 864 neonatal dried blood spot specimens were analyzed.Out of 604 positive samples primarily screened by Hb electrophoresis, the positive rate was 8.80%, 343 samples carried thalassemia gene mutations secondarily confirmed by genotyping test, the carrying rate was 5%(343/6 864), among which 81.92 % (281/343) were α-thalassemia, 16.62% (57/343) were β-thalassemia and 1.46% (5/343) were both α- and β-thalassemia.In those α-thalassemia, the deleted α-gene types occupied 89.68%(252/281), the major genotype was --^SEA /αα; the mutated α-gene types occupied 4.98%(14/281), the major genotype was α^QSα/αα. In those β-thalassemia, there were 9 genotypes, the major genotype was CD41-42/N, occupying 61.40%(35/57).

The neonates have a relatively high carrying rate of thalassemia gene mutations in Haikou city, the genotype composition has geographical characteristics, and the major type is α-thalassemia.The method of using heel dried blood spot specimens on filter paper to screen thalassemia among neonates is advantageous and worthy of advocation.(Chin J Lab Med, 2018, 41: 132-135)

Neonates; Dried blood spot; Thalassemia; Screening; Genotype