Trisomy 4p syndrome: A case report with review

We present a case with trisomy of the short arm of chromosome 4, i.e., 46,XX,der(22)t(4;22)(p12;11.2). The most notable clinical findings included: prominent forehead, hypertelorism, small, bulbous nose with depressed and broad bridge, low hairline, retrognathia, notched auricular helix, rocker-bottom feet with prominent heel, arachnodactyly and comptodactyly. An additional, unique finding in our case is the presence of 13 ribs. In the past, the precise characterization of cases with trisomy for the 4p segment has been difficult by routine cytogenetic techniques because the bands involved in this abnormality are quite variable. We used the FISH technique, applying a battery of probes to delineate the genomic morbidity at the molecular level. In our case, the entire short arm is in the trisomic state, yet it could not be identified as a distinct syndrome prior to cytogenetic evaluation. The phenotypic spectrum associated with this gross chromosomal abnormality has been the subject of debate and scrutiny. We provided a comprehensive review of 64 cases and it is concluded that the clinical manifestations of the pure trisomy 4p syndrome are associated with trisomy of the distal two thirds to the entire p arm and that the additional material does not cause a more severe phenotype.more » Therefore, the molecular characterization of the short arm of chromosome 4 (4p) may be imperative in order to correlate the clinical expression with chromosome bands and ultimately with specific gene(s) in future cases.« less