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Hb Footscray, alpha 133(H16) Ser-->Arg, is a newly described hemoglobin variant found in an adult male of Polish-Hungarian descent. Hematological data and stability by the isopropanol stability test were normal. The abnormal hemoglobin comprised 15% of total hemoglobin and migrated as a split band in the Hb F position on cellulose acetate at pH 8.6. Like Hb Manitoba, which is also a Ser-->Arg mutation and occurs in a very similar spatial position, the split bands presumably arise from the formation of asymmetric hybrids between Hb Footscray and Hb A.

Mutations at positions beta IVS1-6, beta IVS1-110, and beta 39 of the beta globin gene are responsible for the three most common thalassemic genes in the Mediterranean population. The polymerase chain reaction (PCR) was employed to amplify a 536 base pair segment surrounding this region. Nonradioactive labelling of an oligonucleotide probe, specific for the beta IVS1-110 mutation, was achieved by incorporation of biotin-16-dUTP into a standard 3'-end labelling procedure. This probe was subsequently hybridized with the PCR amplification product and permitted detection of the mutant gene in a homozygous beta thalassemic child by a simple colour detection method using a streptavidin-alkaline phosphatase conjugate and NBT/BCIP (nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate) substrate. A known cloned mutant gene was similarly detected. Results could be obtained within 48 hr. These findings suggest that such an approach could provide a rapid and specific means for detection of beta thalassemic mutations without the need for radioactive probes.

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