Loss of heterozygosity of p53 in congenital sacrococcygeal teratomas

Congenital sacrococcygeal teratoma (CSCT) is the most common germ cell tumor of infancy and childhood. The tumor is benign, and consists of fully differentiated mature tissues but may also contain immature tissues derived from all three germinal layers. It is usually diagnosed at birth. Mutations of the p53 gene have been found in more than 50% of human cancers, however, there are few data regarding the expression of p53 in CSCT. In this study we analyzed loss of heterozygosity (LOH) of p53 in nine CSCT by polymerase chain reaction/ restriction fragment length polymorphism (PCR/RFLP) based on two polymorphous sites (Bst U1 and Msp 1). CSCTs were diagnosed in 8 female and 1 male children aged from 3-30 days. The tumors measured from 5.5 to 17 cm in diameter at the largest point. LOH was detected in one tumor sample. Six samples were non-informative (homozygous) for both analyzed markers, while two samples were informative for BstUI, but without LOH in the tumor tissue. p53 positive immunostaining was found in 4 tumors. It seems that LOH of p53 is a rare genetic event in congenital CSCT. However, it is obvious that more studies on larger groups of patients are needed.