MEDICOGENETIC AND CYTOGENETIC STUDY OF A FAMILY WITH HIGH PREDISPOSITION TO MALIGNANT DISEASE IN GASTROINTESTINAL-TRACT

In a family consisting of 48 persons with high predisposition to famil ial stomach cancer (SCr), SCr was diagnosed in 8 persons (I-2; II-1,3, 4; III-1,2,3,4). Moreover, one woman (III-8) had bilateral breast canc er and two (proband: IV-1 and her father's cousin: III-10) chronic gas tritis. The proband, her father's cousin, his sister (III-11) and the proband's sister (IV-2) were examined clinically and cytogenetically ( with the metaphase method on blood lymphocytes with G-banding of chrom osome 21: (p12-pter) in 100% of cells on the basis of chromosomal inst ability; besides, the complex translocation in chromosome 2 in 4% of c ells and the increase of q-arm of chromosome 21 was found in 2% of cel ls. The proband's sister (IV-2) had 3% of cells with polyploidy, the d el 1 (p34-pter) in 1% of cells and the del 7 (p21-pter) in 4% of cells . The cytogenetic examination of the proband's uncle (III-10), carried out 3 times, revealed the case of the proband, endomitosis in 2% of c ells, polyploidy in 2% of cells and hyperaneuploidy in 4% of cells. Hi s sister (III-11) had 4% of cells with endomitosis, 3% of cells with c hromosome and chromatid breaches, an increase of the p-arm of chromoso me 21 in 100% of cells and the loss of 7p in 2% of cells. The nature o f the phenomenon in chromosome 21 and the translocations in the member s of this family is here discussed. The cytogenetic examination is cur rently ongoing.