Biomedical subjects
Publications and source records attributed to Chantal Farra.
Approximately 40 patients with terminal duplication of the distal short arm of chromosome 7 have been reported, the smallest being dup(7)(p21). We report here on a patient with a smaller duplication, dup(7)(p22.1), detected on G-banding and characterized by array-CGH. We establish phenotype-karyotype correlations with the reported patients with other 7p duplications.
Neuroblastomas, tumors of the sympathetic nervous system, account for 7-10% of the cancers of childhood. Genetic studies have shown, and this study has confirmed, that neuroblastomas are very heterogeneous; no single genetic change common to all neuroblastomas has yet been identified. One genetic aberration found frequently in this pediatric tumor is MYCN gene amplification. Recently we identified a new subset of tumors showing MYCN gain (small increases in gene number arising from unbalanced translocation). To investigate whether gain precedes amplification or is an independent event, we surveyed 200 primary tumors for MYCN copy number with fluorescence in situ hybridization; 152 of 200 (76%) were MYCN single-copy tumors, whereas 48 of 200 (24%) tumors harbored MYCN abnormalities: 36 of the 48 (75%) had MYCN amplification and 12 (25%) had MYCN gain. Among the 36 with MYCN amplified gene, we found four that also showed gain. In three tumors exhibiting simultaneous gain and amplification, these two events were detected in neighboring cells. In the fourth case we detected only MYCN gain in metastatic neuroblasts in the bone marrow, but both MYCN amplification and gain in the primary tumor. The detailed study of these four cases suggests that there may be several different mechanisms leading to increase in MYCN copy number. Further studies in other human malignancies are necessary to determine whether simultaneous gain and amplification are specific to neuroblastoma or constitute a general mechanism by which tumor cells can acquire selective growth advantage.
OBJECTIVE: Bowing of the long bones can be easily detected on antenatal ultrasound screening, but it is a nonspecific sign that can be associated with a variety of conditions, each denoting a different prognosis. Among these conditions, three well-differentiated bone dysplasias share bowed long bones as a main clinical manifestation. Campomelic dysplasia and Stüve-Wiedemann syndrome are characterized by a poor prognosis. Conversely, the overall prognosis of children affected with kyphomelic dysplasia is good, the intelligence and motor development are normal and the radiological abnormalities tend to improve and regress with age. CASE REPORT: We report a case of prenatal detection of short and bowed femora at the 22nd week of gestation. Careful US examination as well as in utero X-ray of the skeleton allowed the exclusion of campomelic dysplasia. In the absence of an unambiguous diagnosis, the pregnancy was continued. At birth, the child presented with clinical and radiological features consistent with a diagnosis of kyphomelic dysplasia. CONCLUSION: This case illustrates the difficulties in making an accurate diagnosis and consequently giving a prognosis when isolated femoral bowing is found on fetal ultrasound examination.