Summary. We describe a sensitive, reliable and reproducible method, based on three multiplex PCR assays, for the rapid detection of seven common a-thalassaemia deletions and one a-globin gene triplication. The new assay detects the a 0 deletions ± ± SEA , ± (a) 20?5 , ± ± MED , ± ± FIL and ± ± THAI in the ®rst multiplex PCR, the second multiplex detects the ±a 3?7 deletion and aaa anti3?7 variant, the third multiplex detects the ±a 4?2 deletion. This simple multiplex method should greatly facilitate the genetic screening and molecular diagnosis of these determinants in populations where athalassaemias are prevalent.

Although mycoplasmas possess a very limited genome, little is known about their virulence mechanisms and methods of persistence in the host. Examination of a wide range of mycoplasma species found considerable variation in their ability to form a biofilm. Mycoplasma putrefaciens, M. cottewii, M. yeatsii, M. agalactiae and M. bovis produced prolific biofilms. Conversely, the highly pathogenic mycoplasma and causative agent of contagious bovine pleuropneumonia, Mycoplasma mycoides subsp. mycoides SC, was unable to produce a biofilm. Biofilms were found to be considerably more resistant to stress, including heat and desiccation, than planktonic cells. A link between the biofilm phenotype and genotype as determined by molecular typing was found for M. bovis. Analysis of biofilms using fluorescent staining combined with confocal microscopy demonstrated that mycoplasma biofilms formed a highly differentiated structure with stacks and channels. Biofilm formation may indicate that mycoplasmas are capable of surviving in the environment.

We report a Thai family in which five members are Hb G-Makassar heterozygotes and one member is, in addition, a heterozygote for beta0-thalassemia (IVS-I-1, G-->T). We confirm that the previously presumed mutation at codon 6 of the beta-globin gene is GAG-->GCG. Hb G-Makassar heterozygotes are asymptomatic and hematologically normal. The Hb G-Makassar/beta0-thalassemia compound heterozygote has features of thalassemia minor. A simple and rapid polymerase chain reaction-restriction fragment length polymorphism for the detection of Hb G-Makassar is described.