IADR Abstract Archives
Exploring the Genetic Etiology of Molar Root-Incisor Malformation.
Objectives: Molar root-incisor malformation (MRIM) is a recently described anomaly that presents alterations in the root structure of deciduous second molars, permanent first molars and crown of permanent upper central incisors. Its etiology is undetermined, but it has recently been associated with alteration of the TCTEX1D2 gene. The objective of this study was to detect a 2.2 Kb deletion of the TCTEX1D2 gene, which includes the entire exon 3 plus flanking intron sequences, in patients diagnosed with MRIM and healthy control subjects.
Methods: In this cross-sectional study, a family composed of a healthy father and mother and a child affected with MRIM were recruited, who signed an informed consent. As controls, anonymized samples of 100 subjects without MRIM were included. Genomic DNA was purified from blood using the QIAamp DNA Blood Midi Kit, according to the manufacturer's instructions. The deletion was identified by Polymerase Chain Reaction (PCR) with specific primers, designed with the Primer3 v4.0 program, which originate a 310 bp amplicon corresponding to exon 3. If there is a deletion, there will be no amplification and if the sequence is normal, the 310 bp fragment is obtained. After determining the optimal alignment conditions of the primers and identity of the amplified fragment, the gDNA samples were subjected to PCR. Visualization of the amplicon was performed by agarose gel electrophoresis, safeview staining, and UV transillumination.
Results: Amplification of exon 3 of the TCTEX1D2 gene in 103 samples revealed that both the proband and his parents, and all control samples, presented the 310 bp fragment, corroborating the absence of this mutation. However, the existence of mutations in other regions of the gene cannot be ruled out.
Conclusions: The analyzed family does not present the 2.2 Kb deletion mutation that includes exon 3 of the TCTEX1D2 gene.
Methods: In this cross-sectional study, a family composed of a healthy father and mother and a child affected with MRIM were recruited, who signed an informed consent. As controls, anonymized samples of 100 subjects without MRIM were included. Genomic DNA was purified from blood using the QIAamp DNA Blood Midi Kit, according to the manufacturer's instructions. The deletion was identified by Polymerase Chain Reaction (PCR) with specific primers, designed with the Primer3 v4.0 program, which originate a 310 bp amplicon corresponding to exon 3. If there is a deletion, there will be no amplification and if the sequence is normal, the 310 bp fragment is obtained. After determining the optimal alignment conditions of the primers and identity of the amplified fragment, the gDNA samples were subjected to PCR. Visualization of the amplicon was performed by agarose gel electrophoresis, safeview staining, and UV transillumination.
Results: Amplification of exon 3 of the TCTEX1D2 gene in 103 samples revealed that both the proband and his parents, and all control samples, presented the 310 bp fragment, corroborating the absence of this mutation. However, the existence of mutations in other regions of the gene cannot be ruled out.
Conclusions: The analyzed family does not present the 2.2 Kb deletion mutation that includes exon 3 of the TCTEX1D2 gene.