MP76-09 DIFFERENTIATING KLINEFELTER SYNDROME FROM OTHER ETIOLOGIES OF AZOOSPERMIA USING MICRORNA

Abstract

INTRODUCTION AND OBJECTIVES: The diagnosis of Klinefelter Syndrome (KS) is made using peripheral blood, which may not reflect genetic aberrations in the gonads. Thus far, exome sequencing has not been successful in the diagnosis of male infertility. MicroRNAs (miRs) are short RNAs that are often differentially expressed in different tissues and disease states. Our objective was to profile miR expression in testicular tissue from patients undergoing microdissection testicular sperm extraction (microTESE) or testis biopsy in order to characterize expression patterns across different karyotypes and stages of spermatogenesis and to develop new testing modalities for male infertility. METHODS: RNA was extracted from testicular tissue from five patients with KS and nonobstructive azoospermia (NOA) as well as from patients with normal male karyotypes, including four patients with obstructive azoospermia and normal testis histology, five patients with NOA and Sertoli cell only syndrome (SCO), and four patients with NOA and early maturation arrest (eMA). MiR profiling was performed using a custom panel (Exiqon) of 22 testis-specific miRs to compare expression across karyotypes. Quantitative polymerase chain reaction was used to generate miR profiles; data analysis was performed using MultiD GenEx software. RESULTS: MicroRNA profile analysis using the 22 miR panel reliably differentiated KS patients from those with normal karyotype. The panel also differentiated patients with normal testis histology from those with SCO, but patients with eMA clustered both with patients with normal histology and SCO patients (dendrogram). CONCLUSIONS: Profiling the pattern of testicular miR expression in patients with NOA is a novel method for diagnosing KS, and may also provide information about likelihood of spermatogenesis. The differential expression of the miRs in this panel shows a strong correlation with testicular histology and further work may reveal the role of miRs as novel regulatory factors of mRNA.