CFTR and male infertility: A sizable fraction of the low-complexity variants (5,254, 70.8%) were alterations at the CFTR intronic poly-T/poly-TG site, which, depending on diplotype, confer moderate risk for pancreatitis, respiratory disease, and male infertility.29 Excluding CFTR, 2,169 other low-complexity variants were uncovered in 233 different genes, comprising 1.7% of all P/LP findings.