Instability of the heterochromatic centromeric regions of chromosomes 1 associated with immunodeficiency was found in a 3 and half months old girl. The case was referred to Department of Genetics, Global Reference Laboratory, Metropolis Healthcare Ltd, Mumbai with the suspicion of Downs Syndrome for chromosomal karyotyping. This patient had facial anomalies in addition to combined immunodeficiency and chromosomal instability. Stretching of the heterochromatic centromeric regions of chromosomes 1 and homologous and non-homologous associations of these regions were the most common cytogenetic findings in this patient. Multi-branched configurations and whole arm deletions of chromosomes 1 were also found. Comparing clinical and chromosomal data we conclude that the patient was suffering from immunodeficiency, centromeric heterochromatin instability and facial syndrome. The chromosomal karyotyping report was showing instability around vicinity of chromosome 1 and various abnormalities around vicinity of both chromosomes 1 were found in form of random breakages of chromosome 1, fragile sites, deletions/duplications of small and long arm, extra copies of chromosome 1 with rosette formations, exchange of arms and partial aneuploidies of chromosome 1. Further, the investigations regarding the immune status revealed that the level of IgM (5.98 mg/dl), IgA (<6.16mg/dl) and IgG (92.10 mg/dl) subgroup of immunoglobulin was very low. The results were consistent with The Immunodeficiency, Centromeric region instability, Facial anomalies (ICF) syndrome. Second sample from the patient for molecular studies could not be collected and performed since the patient failed to survive after 3 and half months.
New aspects on chromosomal instability: Chromosomal break-points in Fanconi anemia patients co-localize on the molecular level with fragile sites
