CONTRIBUTION OF KARYOTYPE IN THE DIAGNOSI S OF IMMUNE-DEFICIENCY - REPORT OF A CASE OF IMMUNE-DEFICIENCY ASSOCIATED WITH CHROMOSOMAL INSTABILITY

The authors report the case of a child presenting with a complex immun e deficiency associated with facial dysmorphia. The karyotype showed a bnormalities in the form of premature division of the centromeres and chromosomal ruptures, suggesting the dia gnosis of immune deficiency a ssociated with chromosomal instability, although this case did not app ear to correspond to a previously described syndrome. Syndromes with c hromosomal instability such as ataxiatelangiectasia, ICF syndrome, Fan coni anaemia, Bloom syndrome, Nijmegen syndrome, and Seckel syndrome, frequently present in the form of a complex immune deficiency. They mu st be considered when this deficiency is associated with other manifes tations, especially dysmorphia. By demonstrating the abnormalities obs erved in these syndromes (premature division of the centromeres, chrom osomal ruptures, deletions, translocations, branched chromosomes, radi al chromosome arrangement, sensitivity to ionizing radiation, etc.), t he karyotype, performed on lymphocytes, can be a useful guide to the d iagnosis.