CFTR and intestinal obstruction in the newborn due to guanylate cyclase 2C deficiency: The 1677delTA variant (a 2bp deletion in exon 10 of the CFTR gene) is common in the Black Sea basin (the highest frequency being detected in Georgia) and is associated with a severe CF phenotype, with a high rate of early mortality in homozygotes, and possibly with an increased risk of meconium ileus [48,49].