Globozoospermia is mainly due to DPY19L2 deletion via non-allelic homologous recombination involving two recombination hotspots

Hum Mol Genet. 2012 Aug 15;21(16):3695-702. doi: 10.1093/hmg/dds200. Epub 2012 May 31.

Abstract

To date, mutations in two genes, SPATA16 and DPY19L2, have been identified as responsible for a severe teratozoospermia, namely globozoospermia. The two initial descriptions of the DPY19L2 deletion lead to a very different rate of occurrence of this mutation among globospermic patients. In order to better estimate the contribution of DPY19L2 in globozoospermia, we screened a larger cohort including 64 globozoospermic patients. Twenty of the new patients were homozygous for the DPY19L2 deletion, and 7 were compound heterozygous for both this deletion and a point mutation. We also identified four additional mutated patients. The final mutation load in our cohort is 66.7% (36 out of 54). Out of 36 mutated patients, 69.4% are homozygous deleted, 19.4% heterozygous composite and 11.1% showed a homozygous point mutation. The mechanism underlying the deletion is a non-allelic homologous recombination (NAHR) between the flanking low-copy repeats. Here, we characterized a total of nine breakpoints for the DPY19L2 NAHR-driven deletion that clustered in two recombination hotspots, both containing direct repeat elements (AluSq2 in hotspot 1, THE1B in hotspot 2). Globozoospermia can be considered as a new genomic disorder. This study confirms that DPY19L2 is the major gene responsible for globozoospermia and enlarges the spectrum of possible mutations in the gene. This is a major finding and should contribute to the development of an efficient molecular diagnosis strategy for globozoospermia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gene Deletion*
  • Homologous Recombination*
  • Homozygote
  • Humans
  • Infertility, Male / genetics*
  • Linkage Disequilibrium
  • Male
  • Membrane Proteins / genetics*
  • Point Mutation
  • Repetitive Sequences, Nucleic Acid

Substances

  • DPY19L2 protein, human
  • Membrane Proteins