Design of Polymerase Chain Reaction Initiators and Their Function to Identify FAH Mutations in Type I Tyrosinemia

Tyrosinemia is a recessive autosomal genetic disease due to the defect of fumaril acetoacetate hydrolase (FAH). About 40 pathogenic mutations have been reported for this gene. The aim of the present study was to determine and design polymerase chain reaction primers and their ability to identify FAH gene mutations causing type I tyrosinemia.

In the present case-control study, 12 patients were recruited and divided into two equal groups: first six patients with type I tyrosinemia and second group six patients without informed consent. Blood samples were taken. Then, the DNA was extracted. The polymerase chain reaction initiator was designed for parts of the gene which reported in previous studies of the mutation. The specificity of primers designed with online databases was evaluated. Gene fragments were amplified by polymerase chain reaction. Then the amplified fragments were sequenced after purification. Finally the sequenced regions analyzed by Vector NTI software.

Designed primers amplified FAH gene segments specifically and sequencing of amplified segments revealed +709 C>T mutation in exon 10 of FAH gene. The patient's parents were carriers of this genetic mutation. In the control group no mutation was found in the FAH gene.

  The nonsense mutation 709 C> T is a pathogenic mutation in the FAH gene that was previously reported only in Turkey. The designed primers were cost-effective and specifically able to amplify the FAH gene. These primers can also be used to identify carriers of the disease as well as prenatal diagnosis of type I tyrosinemia.