Diagnostic and screening method for male infertility

Abstract

The present invention relates to a novel diagnostic method for the detection of infertility in males. In particular, the present invention relates to a diagnostic method for detecting the presence or absence of a mutation or mutations in the POLG gene encoding mitochondrial DNA polmerase in a biological sample. The invention relates also to the use of a mutant POLG gene in the detection of infertility in males and in the screening of human populations for the presence of such mutation or mutations as a predictive test for male infertility. The invention also relates to the use of the POLG gene as an indicator of other pathological conditions associated with or related to male infertility, including those manifesting in women.

1 . A method for the diagnosis of male infertility, characterized by detecting the presence or absence of a mutation or mutations in the POLG gene encoding the catalytic subunit of mitochondrial DNA polymerase in a biological sample.  
     
     
         2 . A method for population-based screening for genetic predisposition to male infertility, characterized by detecting the presence or absence of a mutation or mutations in the POLG gene encoding the catalytic subunit of mitochondrial DNA polymerase in a biological sample.  
     
     
         3 . A method of  claim 1 , characterized in that the mutation or mutations are located in the trinucleotide (CAG) microsatellite repeat of the POLG gene.  
     
     
         4 . A method of  claim 3 , characterized in that the mutation or mutations are located in both alleles of the POLG gene in the trinucleotide (CAG) microsatellite repeat of the POLG gene.  
     
     
         5 . A method of  claim 1 , characterized in that the mutation or mutations are located in or near a coding region of the POLG gene.  
     
     
         6 . A method of  claim 1 , characterized in that one mutation or mutations are located in one allele of the POLG gene in the trinucleotide (CAG) microsatellite repeat and another mutation or other mutations in the other allele of the mutant POLG gene in or near a coding region of the gene.  
     
     
         7 . A method of  claim 1 , characterized in that the detection of the mutation is performed using a gene-technological method.  
     
     
         8 . A method of  claim 7 , characterized in that the detection of the mutation or mutations is performed using the polymerase chain reaction (PCR) or other thermal cycler-based DNA synthetic techniques, molecular cloning in a plasmid or other suitable vector, detection of length variants in a DNA sample by agarose or polyacrylamide gel electrophoresis, gel or capillary electrophoresis and analysis of products tagged with a fluorescent or other label incorporated into the DNA, DNA sequence determination and any heteroduplex-based or similar methods for detecting base mismatches or length variants.  
     
     
         9 . A method of  claim 1 , characterized in that the detection of the mutation or mutations is performed using an immunological method, such as a Western analysis, immunohistology or immunoassay, for characterization of a mutant gene or gene product.  
     
     
         10 . A method of  claim 9 , characterized in that the detection of mutation or mutations is performed using immunohistology.  
     
     
         11 . A use of a mutant form of the POLG gene encoding the catalytic subunit of mitochondrial DNA polymerase for the diagnosis or prediction of male infertility.  
     
     
         12 . A use of a mutant form of the POLG gene encoding the catalytic subunit of mitochondrial DNA polymerase as a diagnostic agent.  
     
     
         13 . A diagnostic kit, characterized in that it comprises reagents capable of identifying the presence or absence of a mutation or mutations in the POLG gene encoding the catalytic subunit of mitochondrial DNA polymerase.  
     
     
         14 . A use of the POLG gene as an indicator of other pathological conditions associated with or related to male infertility, including those manifesting in women.