COMPLEX CHROMOSOMAL REARRANGEMENTS ASSOCIATED WITH CONGENITAL ERYTHROPHAGOCYTOTIC HISTIOCYTOSIS

We describe a patient with a congenital malignant blood disorder and a constitutional de novo chromosomal rearrangement that includes four b reakpoints. By conventional cytogenetic analysis an obviously reciproc al balanced translocation with the breakpoints 1p36 and 5q11.2 was dia gnosed. Due to a suspicious dark band in the breakpoint area of Ip a m ore detailed analysis of the breakpoints was performed using microdiss ection and reverse chromosome painting. This revealed a small inversio n at 1p36 that must have occurred prior to the reciprocal translocatio n. The three breakpoints in chromosome 1 (1p36.11, 1p36.21 and 1p36.31 ) are within or close by regions known to contain tumor suppressor gen es. The chromosomal rearrangement might have resulted either in a subm icroscopic deletion, in loss of heterozygosity of one or more imprinte d genes, or in gene position effects as possible explanations for the clinical course of our patient.