Hpa-I polymorphism and the sickle gene in Nigerians

The Hpa-I restriction fragment length polymorphism linked to the beta globin genes was studied in 181 Nigerian subjects. The beta S gene was found to be linked to the 13 kilobase (kb) Hpa-I fragment in 98.4 percent while 1.6 percent was linked to the Hpa-I 7.6 kb fragment. The majority of beta A genes (94.2%) was found to be linked to either the 7.6 or 7.0 kb fragment whilst the remainder (5.8%) was linked to the 13.0 kb. The beta A 13 kb linkage and the small proportion of the beta S genes linked to the 7.6 kb fragment would lessen the accuracy of the Hpa-I polymorphism in the prenatal diagnosis of sickle cell anaemia in this population.