[Collagen type I gene polymorphism in children and young adults with neoplastic disease]

Osteoporosis has multifactorial and poligenetic basis. One of the most important genetic factor, often associated with increased susceptibility to fractures and lower bone mass, is the polymorphism of the gene of collagen type I alpha 1 (COLIA1). Significant ethnic differences were found in the distribution of specific COLIA1 genotypes. Comorbidity of potentially unfavourable genotype and childhood cancer and its' treatment could enhance its' negative influence on bone. THE AIM OF THE STUDY was to evaluate the frequency of collagen type I alpha 1 gene polymorphism in children from the north-eastern region of Poland, who underwent cancer.

The COLIA1 gene polymorphism was established by RFLP (restricted fragment length polymorphism) method using polymerase chain reaction (PCR) in 215 patients (89 girls and 126 boys) treated for cancer at the Department of Pediatric Oncology of Medical University of Bialystok. Control group consisted of 51 healthy children from the same region of Poland.

In the group of children with neoplastic disease we found the following distribution of COLIA genotypes: SS - 66,5%, Ss - 33,02% and ss - 0,47%. In the control group the SS genotype was more frequent (80,95%). In children treated for leukemia allel 's' was found to be more frequent (SS - 58%, Ss - 41%).

It seems that presence of 's' allel, which was proved to be concomitant with fractures occurrence in adults, should be also considered as an additional negative element of the bone structure in children, especially when other environmental factors are present (complex antineoplastic treatment, bone marrow infiltration and cancer itself). Genetic factors, such as polymorphism of collagen type I, should be taken under consideration in diseases which can potentially lead to osteoporosis.