Studying on the method of nested PCR combined with pedigree analysis of diagnostic value in rare alpha thalassemia.

The proband and 12 family members were screened for thalassemia though blood routine analysis, hemoglobin electrophoresis and erythrocyte fragility tests. PCR- reverse dot blot hybridization (RDB) technique was used in the diagnosis of non-deletion point mutations of alpha thalassemia and 17 beta thalassemia gene mutation. Gap of polymerase chain reaction (Gap-PCR) was used in the analysis of alpha thalassemia gene deletion type. The nested PCR was used to detect HK alpha gene type, and drawing the alpha thalassemia gene genetic map was drawn.

In 12 family members, there were 4 cases in which the MCV, MCH, and erythrocyte fragility were lower than the normal reference values, and the remaining 8 cases showed no abnormal hematological parameters. All of the 12 cases showed that the hemoglobin electrophoresis was normal. In the 12 family members, there were 2 cases of --^SEA/αα gene, 2 cases of αα/αα gene, 6 cases of HKαα/αα gene, and 2 cases of HKαα--^SEA gene. None of the 17 common beta thalassemia or 3 common non-deletion alpha thalassemia were detected.

Nested PCR combined with pedigree analysis method was found a rare thalassemia gene type and an important way to reduce the misdiagnosis of HKαα thalassemia.

Alpha-Thalassemia; HKαα; Prenatal diagnosis; Pedigree