INTRODUCTION.
Chromosome #3 has two (2) different genes that have been identified in hepatoblastoma: CTNNB1on 3p22.1 & PIK3CA on 3q26.32. Hepatoblastoma is a malignant liver cancer occurring in infants and children and composed of tissue resembling fetal liver cells, mature liver cells, or bile duct cells. They usually present with an abdominal mass. The disease is most commonly diagnosed during a child’s first three years of life. Alpha-fetoprotein (AFP) levels are commonly elevated, but when AFP is not elevated at diagnosis the prognosis is poor.
There is evidence hepatoblastoma is caused by mutation in the phosphatidylinositol 3-kinase (PIK3CA) gene on cytogenetic location 3q26.32 and genomic coordinates 3:179,148,126-179,240,093. The screenshot of the PIK3CA gene 91,968 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides PIK3CA in the cytogenetic location are listed BENEATH.
| Coordinate | Symbol | Genomic Name |
| 3:174,440,982 | NAALADL2 | N-acetylated alpha-linked acidic dipeptidase-like 2 |
| 3:177,019,344 | TBL1XR1 | Transducin-beta-like 1 receptor 1 |
| 3:178,536,436 | KCNMB2 | Potassium channel, calcium-activated, large, M, beta 2 |
| 3:179,017,223 | WIG1 | Wildtype p53-induced gene |
| 3:179,148,126 | PIK3CA | Phosphatidylinositol 3-kinase, catalytic, alpha polypeptide |
| 3:179,239,703 | KCNMB3 | Potassium large conductance calcium channel, M, beta 3 |
| 3:179,322,876 | ZNF639 | Zinc finger protein 639 |
| 3:179,347,709 | MFN1 | Mitofusin 1 |
| 3:179,396,088 | GNB4 | Guanine nucleotide-binding protein, beta-4 |
| 3:179,562,926 | ACTL6A | Actin-like 6A |
