Autosomal recessive long QT syndrome, type 1 in eight families from Saudi Arabia.

BACKGROUND: One of the most common primary cardiac arrhythmia syndromes is autosomal dominant long QT syndrome, type 1 (LQT1), chiefly caused by mono-allelic mutations in the KCNQ1 gene. Bi-allelic mutations in the KCNQ1 gene are causal to Jervell and Lange-Nielsen syndrome (JLNS), characterized by severe and early-onset arrhythmias with prolonged QTc interval on surface ECG and sensorineural deafness. Occasionally, bi-allelic mutations in KCNQ1 are also found in patients without any deafness, referred to as autosomal recessive long QT syndrome, type 1 (AR LQT1). METHODS: We used Sanger sequencing to detect the pathogenic mutations in KCNQ1 gene in eight families from Saudi Arabia with autosomal recessive LQT1. RESULTS: We have detected pathogenic mutations in all eight families, two of the mutations are founder mutations, which are c.387-5T>A and p.Val172Met/p.Arg293Cys (in cis). QTc and cardiac phenotype was found to be pronounced in all the probands comparable to the cardiac phenotype in JLNS patients. Heterozygous carriers for these mutations did not exhibit any clinical phenotype, but a significant number of them have sinus bradycardia. CONCLUSION: To the best of our knowledge, this is the first description of a large series of patients with familial autosomal recessive LQT, type 1. These mutations could be used for targeted screening in cardiac arrhythmia patients in Saudi Arabia and in people of Arabic ancestry.

Expression of S-adenosyl methionine decarboxylase gene for polyamine accumulation in Egyptian cotton Giza 88 and Giza 90.

Developing drought tolerance in Egyptian cotton varieties is a strategic goal considering the need to expand cotton cultivated area and water scarcity in the Nile valley. In the present study, increasing levels of polyamine accumulation via expressing S-adenosyl methionine decarboxylase (SAMDC) gene was the main goal. SAMDC cDNA isolated from Saccharomyces cerevisiae isolate was isolated and genetically engineered into Egyptian cotton varieties Giza 88 as an extra long staple and Giza 90 as a long staple by means of particle bombardment through meristem transformation.T(0) transgenic plants were screened using basta herbicide (200 mg/l). RT- PCR analysis was used to confirm gene expression while gene integration was confirmed by Southern blot analysis. Control plants from Giza 88 and Giza 90 were subjected to drought regime using different concentrations of PEG 6000 (2.5%, 5%, 7.5%, 10%, 12.5%, 15%, 17%, and 20%) for 9 hrs to record drought stress symptoms and determine the potential concentration level for inducing polyamine accumulation. 17% of PEG 6000 was considered the sublethal concentration showing drought stress symptoms and therefore was used as potential stress concentration for estimating the level for spermine accumulation in both control and transgenic Giza varieties. T(1) transgenic plants grown under induced drought stress regime were tested positive for gene integration and expression and subjected to HPLC analysis to determine levels of spermine as polyamine accumulated compound in response to drought stress regime. Elevated spermine accumulation in Egyptian cotton varieties Giza 88 and Giza 90, were compared as non transgenic plants grown under same induced drought conditions with T(1) transgenic plants using reverse-phase HPLC analysis. Elevated spermine accumulation expressing SAMDC gene reflect main cause for increasing drought tolerance in both transgenic varieties.