Variant , Defective piRNA Processing, and Azoospermia.

TitleVariant , Defective piRNA Processing, and Azoospermia.
Publication TypeJournal Article
Year of Publication2021
AuthorsNagirnaja L, Mørup N, Nielsen JE, Stakaitis R, Golubickaite I, Oud MS, Winge SB, Carvalho F, Aston KI, Khani F, van der Heijden GW, C Marques J, Skakkebaek NE, De Meyts ERajpert-, Schlegel PN, Jørgensen N, Veltman JA, Lopes AM, Conrad DF, Almstrup K
JournalN Engl J Med
Date Published2021 08 19
KeywordsAdult, Azoospermia, Biopsy, Exoribonucleases, Gene Expression, Humans, Infertility, Male, Male, Meiosis, Mutation, Phenotype, Polymerase Chain Reaction, RNA, Small Interfering, Sequence Analysis, RNA, Testis, Whole Exome Sequencing

BACKGROUND: P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are short (21 to 35 nucleotides in length) and noncoding and are found almost exclusively in germ cells, where they regulate aberrant expression of transposable elements and postmeiotic gene expression. Critical to the processing of piRNAs is the protein poly(A)-specific RNase-like domain containing 1 (PNLDC1), which trims their 3' ends and, when disrupted in mice, causes azoospermia and male infertility.

METHODS: We performed exome sequencing on DNA samples from 924 men who had received a diagnosis of nonobstructive azoospermia. Testicular-biopsy samples were analyzed by means of histologic and immunohistochemical tests, in situ hybridization, reverse-transcriptase-quantitative-polymerase-chain-reaction assay, and small-RNA sequencing.

RESULTS: Four unrelated men of Middle Eastern descent who had nonobstructive azoospermia were found to carry mutations in : the first patient had a biallelic stop-gain mutation, p.R452Ter (rs200629089; minor allele frequency, 0.00004); the second, a novel biallelic missense variant, p.P84S; the third, two compound heterozygous mutations consisting of p.M259T (rs141903829; minor allele frequency, 0.0007) and p.L35PfsTer3 (rs754159168; minor allele frequency, 0.00004); and the fourth, a novel biallelic canonical splice acceptor site variant, c.607-2A→T. Testicular histologic findings consistently showed error-prone meiosis and spermatogenic arrest with round spermatids of type Sa as the most advanced population of germ cells. Gene and protein expression of PNLDC1, as well as the piRNA-processing proteins PIWIL1, PIWIL4, MYBL1, and TDRKH, were greatly diminished in cells of the testes. Furthermore, the length distribution of piRNAs and the number of pachytene piRNAs was significantly altered in men carrying mutations.

CONCLUSIONS: Our results suggest a direct mechanistic effect of faulty piRNA processing on meiosis and spermatogenesis in men, ultimately leading to male infertility. (Funded by Innovation Fund Denmark and others.).

Alternate JournalN Engl J Med
PubMed ID34347949
Grant ListIF/01262/2014 / / Fundação para a Ciência e a Tecnologia /
P50HD096723 / NH / NIH HHS / United States
R01HD078641 / NH / NIH HHS / United States
918-15-667 / / Nederlandse Organisatie voor Wetenschappelijk Onderzoek /
209451 / WT_ / Wellcome Trust / United Kingdom
14-2013-4 / / Innovationsfonden /
P50HD096723 / NH / NIH HHS / United States
R01HD078641 / NH / NIH HHS / United States
209451 / WT_ / Wellcome Trust / United Kingdom
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