ICF SYNDROME WITH VARIABLE EXPRESSION IN SIBS

We describe a new familial case of ICF syndrome (immunodeficiency, cen tromeric instability, facial anomalies) in a woman of 29 years and in her brother of 30 years. The proband showed mental retardation, facial anomalies, recurrent respiratory infections, combined deficit of IgM and IgE immunoglobulin classes, and paracentromeric heterochromatin in stability of chromosomes 1, 9, and 16. The brother had minor signs of the syndrome and had an apparently normal phenotype. Their parents wer e healthy and non-consanguineous. Chromosome anomalies consisted of ho mologous and non-homologous associations, chromatid and isochromatid b reaks, deletions of whole arms, interchanges in the paracentromeric re gion, and multibranched configurations of chromosomes 1, 9, and 16. CD bands and fluorescence in situ hybridisation with alphoid DNA sequenc e probes specific for the centromeres of chromosomes 1 and 16 showed t hat the centromere was not directly implicated in the formation of mul tibranched configurations. These cases indicate the autosomal recessiv e mode of inheritance and the variable expressivity of the ICF syndrom e.