CTG amplification in the DM1PK gene is not associated with idiopathic male subfertility.

BACKGROUND Polymorphism in the CTG triplet number in the myotonic dystrophy type 1 (DM1PK) gene has been proposed as being associated with idiopathic azoospermia. The aim of this study was to investigate whether the CTG trinucleotide amplification in the DM1PK gene is associated with male subfertility. METHODS We evaluated 107 subfertile patients, male partners of infertile couples, affected by non-obstructive azoospermia (n = 38) and oligoasthenoteratozoospermia (OAT) (n = 69), and 102 men with proven fertility. Main outcome measures were CTG repeat size in the DM1PK gene, testicular volume, sperm concentration, rapid progressive motility, normal morphology, serum FSH levels, testicular histology and Johnsen score. RESULTS In subfertile males, no minimal mutation or mutation carriers were found. The difference in the number of CTG repeat lengths between the groups was not statistically significant (P = 0.825). There was no correlation between the number of CTG repeats and the clinical parameters of subfertile patients: testicular volume, sperm concentration, rapid progressive motility, normal morphology, FSH level, testicular histology and Johnsen score. CONCLUSIONS The number of CTG repeats in the normal or mutational range of DM1PK gene is associated with neither idiopathic male subfertility nor with clinical characteristics of male subfertility.