CFTR and intestinal obstruction in the newborn due to guanylate cyclase 2C deficiency: The meconium ileus association is seen in patient cohorts composed of many different CFTR genotypes, and the effect size is similar in individuals who are Phe508del/Phe508del (OR = 1.41, se = 0.058) versus other CFTR genotypes (OR = 1.32, se = 0.083).