Three new mutations account for the prevalence of glucose 6 phosphate deshydrogenase (G6PD) deficiency in Tunisia.

A previous study on G6PD deficiency carried out on Tunisian population, led to the finding of seven different mutations with the prevalence of G6PD A- variant. This present study reports 23 new unrelated deficient subjects studied at the molecular level to determine the mutation that causes G6PD deficiency. Using PCR-SSCP of coding regions followed by direct sequencing of abnormal pattern, three new mutations were detected. Two of them are polymorphic intronic mutations. The first is IVS-V 655C-->C/T, found in four female subjects with mild deficiency of class III variant. The second is IVS-VIII 43 G-->A, found in three male subjects with mild deficiency of class III variant. The third mutation is in the exon region so that it changes the primary structure of the molecule. It is cited for the first time and named G6PD Tunisia. This variant affects the exon 7 of the gene at genomic position 15435 G→T. Its cDNA position is 93 G→G/T, it changes arg 246 to leu. This mutation was found in one heterozygote female with deficiency of class II who have had hemolytic anemia due to ingestion of fava beans. Finally, G6PD Med variant, reported before in three cases, was also found in five other cases (four heterozygote females and one male hemizygote). These findings first enlarge the spectre of mutations to be ten variant mutations, characterizing the Tunisian population and also contribute with hemoglobin gene research in our laboratory to trace the whole genetic map of Tunisian population.

Population Genetic Analysis Reveals Diversity in Lasiodiplodia Species Infecting Date Palm, Citrus, and Mango in Oman and the UAE.

Lasiodiplodia is a common pathogen causing dieback, gummosis, or root necrosis on the three most important fruit crops in Oman and the United Arab Emirates (UAE): date palm (Phoenix dactylifera), Citrus spp., and mango (Mangifera indica). A study was conducted to examine diversity in 64 Lasiodiplodia isolates infecting date palm (24), Citrus (11), and mango (29) in Oman and the UAE. Identification based on sequences of the internal transcribed spacer (ITS) rDNA and EF1α gene showed that date palm isolates belonged to L. hormozganensis (75% of isolates) and L. theobromae (25%); Citrus isolates belonged to L. hormozganensis (45%), L. theobromae (45%), and L. iraniensis (10%); and mango isolates belonged to L. theobromae (59%), L. iraniensis (34%), and L. hormozganensis (7%). Amplified fragment length polymorphism (AFLP) fingerprinting of the 64 isolates using four primer pair combinations produced 64 genotypes and 972 polymorphic alleles. Cluster analysis separated the isolates into four clusters representing the three species. A higher level of genetic diversity was observed in L. iraniensis (0.3105) compared to L. hormozganensis (0.2503) and L. theobromae (0.2331) in Oman. Analysis of molecular variance (AMOVA) indicated the existence of low levels of genetic differentiation among date palm populations of L. hormozganensis obtained from Oman and the UAE (FST = 0.025) and among populations of L. hormozganensis (0.0485) and L. theobromae (0.0703) from date palm, Citrus, and mango. These findings imply a high rate of movement of L. hormozganensis and L. theobromae isolates among date palm, Citrus, and mango and between the two countries. Findings from the pathogenicity test supported the AMOVA analysis and suggested a lack of host specialization in L. hormozganensis, L. iraniensis, and L. theobromae on date palm, acid lime, and mango. Although this is the first record of L. hormozganensis and L. iraniensis in Oman, the relatively moderate level of genetic diversity in the two species compared to L. theobromae suggests that the two species have been in Oman for a long time but misidentified by morphology and ITS rDNA sequences as L. theobromae. This study is also the first record of date palm and acid lime as natural hosts for L. hormozganensis and the first record of L. hormozganensis in the UAE. The diversity in Lasiodiplodia species affecting date palm, Citrus, and mango in Oman and the UAE should be taken into consideration when planning future management programs for diseases caused by these pathogens.