Familial translocation t(5;11)(q32;q23) resulting in Jacobsen syndrome and distal trisomy 5q31 in a female patient
Background: Jacobsen syndrome is a rare contiguous gene disorder caused by partial deletion of the distal part of the long arm of chromosome 11 (prevalence 1/100,000 live births). Most of the reported cases are caused by de novo deletion and in 15% result from an unbalanced segregation of a familial balanced translocation. The spectrum of clinical symptoms observed in patients with JBS is variable and depends on the size of the deletion. The aim of the study: To describe the phenotypic variation in a patient with Jacobsen syndrome as a result of the segregation of an unusual balanced translocation inherited from her mother. Materials and methods: A detailed clinical analysis of the patient’s condition was performed. The chromosomes were studied through the GTG-banding analysis and FISH withCri-du-Chat Region Probe – LSI EGR1, LSI D5S23, D5S721. Results: The patient has a derivative chromosome 11 with a partial monosomy 11q and a partial trisomy 5q with a phenotype influenced by these two imbalances. The mother showed a 46,XX,t(5;11)(q32;q23) karyotype. Conclusion: Deletion syndromes arising from apparently balanced translocation are unusual ways of presentation in Jacobsen syndrome and should be evaluated carefully when the distal part of chromosome 11q is involved in the rearrangement.