A distinctive pediatric renal neoplasm characterized by epithelioid morphology, basement membrane production, focal HMB45 immunoreactivity, and t(6;11)(p21.1;q12) chromosome translocation.

We report two cases of a hitherto undescribed pediatric renal neoplasm that is distinctive at the morphological, immunohistochemical, ultrastructural, and cytogenetic levels. On light microscopy, the tumors are composed of nests of polygonal, clear to eosinophilic cells associated with a subpopulation of smaller cells that surround hyaline material. Despite their epithelioid morphology, these tumors do not label immunohistochemically for epithelial markers but instead label focally for melanocytic markers HMB45 and Melan A. The hyaline material is positive with periodic acid-Schiff and methenamine-silver histochemical stains, and labels immunohistochemically for type 4 collagen. Ultrastructural examination confirms that it represents basement membrane material. Cytogenetic analysis reveals the identical t(6;11)(p21.1;q12) chromosome translocation as the sole abnormality in these two tumors, confirming their identity and distinctive nature.

Reproductive outcome in 3 families with a satellited chromosome 4 with review of the literature.

We describe 3 families segregating for a translocation of the nucleolus organizer region (NOR) onto chromosome 4. Review of previously reported cases of translocations involving NOR and chromosome 4 shows that these translocations may be associated with variable reproductive outcomes. We provide evidence that imprinting is not the mechanism responsible for the variable reproductive outcomes in the case of satellited 4p chromosomes; this may offer indirect support for a ribosomal gene position effect. Translocated ribosomal genes may influence the expression of neighboring genes and could explain the variable phenotypes in individuals with satellited nonacrocentric chromosomes. We recommend that prenatal counseling of individuals with satellited nonacrocentric chromosomes should be cautious.

SRVX, a sex reversing locus in Xp21.2-->p22.11.

Duplication within Xp21 causes female or intersexual development in human embryos with an XY chromosome complement. We have mapped the responsible gene, SRVX (sex reversal X), in XY-sex-reversed maternal half siblings who had inherited the duplication from their mother. The limited size of the duplication in our cases, relative to its extent in other similar cases, allows assignment of the SRVX locus to Xp21.2-->p22.11. We infer that SRVX is part of a pathway of sex-determining genes that includes SRY and SRA1, the latter recently assigned to chromosome 17q. If mutation of SRA1 or SRVX can reverse the sex of the XY fetus, this would explain why mutation within SRY is found only sporadically in women with XY gonadal dysgenesis.

Mild mandibulofacial dysostosis in a child with a deletion of 3p.

We report on a patient with mild mandibulofacial dysostosis and a small interstitial deletion of 3p, 46,XY,del(3)(p23p24.12). Linkage of Treacher Collins syndrome, the most common of the mandibulofacial dysostoses, to the 5q31.3-->q33.3 region of chromosome 5 has been established. This is the fourth report of a patient with mandibulofacial dysostosis with a chromosome abnormality outside the 5q31.3 area. Mandibulofacial dysostosis is a heterogeneous entity, and evaluation and counseling of affected individuals should be undertaken with caution.

Mosaic Down's syndrome with de novo 45,XX,-21,-22,+t(21q;22q)/46,XX,-21,+t(21q;21q) rearrangement.

The occurrence of mosaic Down's syndrome with two independent Robertsonian translocation cell lines is very rare. Such a patient is reported here, in whom an unbalanced Robertsonian translocation between two chromosomes 21 was detected in the majority of cells. The patient also revealed a minor cell line with a second Robertsonian translocation involving a chromosome 21 and a 22. The chromosome translocations detected in this patient were de novo in origin.

A simple reproducible method for prometaphase chromosome analysis.

A method is described for the analysis of chromosomes in prophase and early metaphase. It involves culturing the lymphocytes in medium RPMI-1640, supplemented with 10% autologous plasma instead of fetal bovine serum. Living cells are treated with actinomycin D and colcemid for 1 h prior to harvest and harvested early at 65 h of incubation, using a hypotonic solution formulated by Ohnuki (1968). The method has been tested on several hundred clinical samples on a routine basis. On average, 30% of the dividing cells were in prometaphase.

Partial deletion 10q.

The patient described represents the first reported case of partial deletion 10q. The patient is compared to the partial trisomy 10q syndrome.

Partial trisomy 15 in a young girl.

Severe mental retardation, growth failure, microcephaly, micrognathia, cleft palate, hooked nose, low-set thin flabby ears, pronounced elongated philtrum, and generalized decreased subcutaneous tissue characterized a 5 year 9 month old female with karyotype 47,XX,+15,del(15)(q15).

Trisomy 13 in a female over 5 years of age.

A case of simple trisomy 13, confirmed by G-banded chromosome analysis, is reported in a Caucasian female over 5 years of age. There is no cytogenetic evidence available for mosaicism in the propositus or her parents. The patient's salient clinical features are: profound mental and motor retardation; microcephaly with trigonocephaly; ear malformations; small, sunken eyes; unusual eyebrows; cleft lip and palate; bulbar nose; coloboma iris; polydactyly; unusual dermatoglyphic patterns; large adductor thumbs; enlarged great toes; multiple capillary haemangiomas; club feet; inguinal and umbilical hernias; hyperconvexed fingernails; and seizure disorder.

Terminal (1)(q43) long-arm deletion of chromosome no. 1 in a three-year-old female.

A 3-year-old Latin female is reported with a terminal deletion of the No. 1 chromosome, karyotype formula 46, XX, del(1) (q43). Principle clinical features include: Anatomic - microcephaly; bilateral, convergent strabismus; epicanthus; brachycephaly; bulbar nose; sparse hair; partial soft tissue syndactylism between 2nd and 3rd fingers which are slightly tapered; whorls on all 10 fingers; mild prognathism; solitary kidney; vaginal stenosis; vesicoureteral reflux; asymmetric feet; and subluxation of peroneal tendons around the fibula with severe pronation and heal valgus deformity. Neurologic - moderate motor and mental retardation; high-pitched, shrill cry; absent pincer grasp at 3 years; and grand mal seizures documented from 9 months of age.

Genetics of Lupinus : IV. Colonization and Genetic Variability in Lupinus succulentus.

Preliminary surveys indicate that most populations of Lupinus succulentus are genetically monomorphic for three flower color loci, viz., BB PP DD. In one small geographic area, a number of populations were polymorphic for the D/d locus. In this case, clinal variation and seasonal variation were found. The S/s locus, affecting seed coat pattern, was polymorphic in a large majority of populations and genetic variation at this locus is present in all but a very few colonies. When subdivisions of five large populations were studied, genetic differentiation was found within two of these populations. Gene frequencies tended toward the limits of zero or one in populations from relatively undisturbed sites but tended toward intermediate values in the more disturbed ruderal populations presumed to be recently colonized. It is concluded that recently colonized populations are not always genetically uniform.