Molecular differential pathology of rhabdomyosarcoma.

Tumors of the soft tissues are classified histogenetically according to their phenotypic resemblance to normal adult tissue. Here we describe molecular approaches that make it possible to distinguish between one class of these tumors, rhabdomyosarcoma, and other small-, round-cell tumors. We show that the ascertainment of specific genotypic changes can be used to distinguish further between the embryonal and alveolar subtypes of rhabdomyosarcoma.

Familial Wiedemann-Beckwith syndrome and a second Wilms tumor locus both map to 11p15.5.

Wilms tumor of the kidney occurs with increased frequency in association with two clinically and cytogenetically distinct congenital syndromes, the Wiedemann-Beckwith syndrome (WBS) and the triad of aniridia, genitourinary anomalies, and mental retardation (WAGR). Constitutional deletions in the latter situation and similar alterations in sporadic Wilms tumors have implicated the chromosomal 11p13 region in neoplastic development. In contrast, some sporadic cases of WBS have been reported to have a constitutional duplication of chromosome 11p15.

Familial predisposition to Wilms' tumour does not map to the short arm of chromosome 11.

Wilms' tumour of the kidney usually occurs sporadically, but can also segregate as an autosomal dominant trait with incomplete penetrance. Patients with the WAGR syndrome of aniridia, genitourinary anomalies, mental retardation and high risk of Wilms' tumour have overlapping deletions of chromosome 11p13 which has suggested a possible location for a Wilms' tumour locus. Moreover, many sporadic tumours have lost a portion of chromosome 11p.

Tissue-specific and developmentally regulated transcription of the insulin-like growth factor 2 gene.

Transcription of the rat and human IGF-2 gene loci is unusually complex. The pattern of expression of these genes varies both between tissues and within a given tissue during different stages of development. Alternative splicing or possibly transcriptional initiation events generate variant IGF-2 mRNAs that contain different 5'-untranslated leader sequences.