Zimmermann-Laband syndrome: further clinical delineation.

Zimmermann-Laband syndrome (ZLS) is an autosomal dominant disorder characterized by gingival fibromatosis, absent or dysplastic distal phalanges, vertebral defects, hepatosplenomegaly, hypertrichosis and sometimes mental retardation. We describe two unrelated patients, a girl aged 9 years and a boy 11 months whose clinical and radiological findings permit us to diagnose the ZLS. Body overgrowth, present in both patients, was identified as a main clinical feature not previously reported as well as the presence in neuroimaging studies of a cavernous hemangioma on the frontal and the left cerebellar regions in the boy. The girl also presented important radiological characteristics such as broad medulary canals and metaphyses of long bones, thin cortices, broad ribs, accelerated skeletal maturation as well as high intelligence level. A wide clinical spectrum in ZLS is also considered.

(CAG)nCAA and GGN repeats in the human androgen receptor gene are not associated with prostate cancer in a French-German population.

Alleles of the CAG and the GGC repeat in the first exon of the human androgen receptor (AR) gene have been shown to be associated with the risk of (advanced) prostate cancer. These studies had been carried out in the United States. We have analysed these polymorphisms in a French-German collection of 105 controls, 132 sporadic cases, and a sample of prostate cancer families comprising 85 affected and 46 not affected family members. The allele distributions were very similar in all four groups and chi square statistics on contingency tables did not detect any significant differences. The relative risk (odds ratio, OR) were calculated using logistic regression and did not reach significance despite sufficient numbers of patients and controls. Typical results were OR = 1.007; 95% Confidence Interval (CI) 0.97-1.1, P = 0.87 for CAG as continuous variable and OR = 1.2 (95% CI 0.7-2.0), P = 0.47 for CAG classes < 22 and > = 22 repeats. Similar results were obtained for subgroups defined by age or Gleason score. We conclude that these polymorphisms can not be used as predictive parameters for prostate cancer in the French or German population.

Functional Xp disomy and hypomelanosis of Ito.

BACKGROUND: Hypomelanosis of Ito (HI) is a neurocutaneous phenotype that reflects different mosaicisms, including functional imbalances secondary to chromosome-X inactivation patterns in certain X;autosome translocation carriers. METHODS: We assessed X inactivation patterns by means of the human androgen receptor (HUMARA) assay and BrdU labeling in affected and unaffected skin of a young female with HI and a de novo t(X;13)(Xp13q;Xq13p). PCR analysis was carried out in DNA extracted from uncultured and cultured skin, whereas the BrdU replication patterns were sought in cultured fibroblasts. Parental DNA was also tested. Fluorescence in situ hybridization (FISH) with X and 13/21 centromere probes (DXZ2 and D13Z1/D21Z1) and a cosmid for the X inactivation center were also performed to refine breakpoint assignments. RESULTS: An X inactivation pattern implying functional Xpter-->q11 disomy was found in DNA extracted from uncultured hypopigmented skin, whereas preferential inactivation of the normal X was observed in uncultured normal skin as well as in cultured fibroblasts (after one passage) from both affected and unaffected skin areas. PCR analysis also showed paternal origin of the translocation. BrdU labeling of metaphases from hypopigmented and normal skin primary cultures showed der(Xq13p) to be inactive in about 25% of the cells. FISH revealed that der(Xp13q) had a compound centromere, whereas der(Xq13p) retained 13 centromere repeats but lacked X centromere sequences. Hence, breakpoints were assigned to Xq11 and 13q10. The X inactivation center cosmid gave a signal on both normal X and der(Xp13q), indicating that the inactivation center was not disrupted by the translocation. CONCLUSIONS: These findings confirm that mosaic functional Xp disomy, rather than disruption of X-linked genes, is associated with HI and involvement of the central nervous system (CNS) in some carriers of a structurally balanced X;autosome translocation.

Hereditary multiple benign cystic epithelioma (multiple trichoepithelioma) with onset at early age.

A mother and a daughter affected with multiple trichoepithelioma were studied. The age of onset of the symptomatology in both was 7-years-old, the daughter being more severely affected than the mother at this age. This early age of onset is an exceptional observation which could be explained by maternal imprinting.

Functional Xp disomy and de novo t(X;13)(q10;q10) in a girl with hypomelanosis of Ito.

We report on a 16 month old girl with hypomelanosis of Ito and a balanced de novo (X;13)(q10;q10) translocation in which the der(Xp13q) had the X centromere (as assessed by FISH with the DXZ3 probe). A functional Xp disomy was shown in a small proportion of cultured lymphocytes by means of a BrdU terminal pulse. This observation supports the notion of a distinct form of hypomelanosis of Ito resulting from a functional Xp disomy.

De novo duplication xq22-q23 in a girl with short stature and gonadal dysgenesis.

A female of 20 years of age with short stature, gonadal dysgenesis and Turner stigmata with a de novo dup Xq22-q23 was studied. The maternal cytogenetic study was normal. This case represents the smallest Xq duplication in an abnormal female. We discuss the possibility of a maternal imprinting.

Sex determination in Ellobius lutescens: the story of an enigma.

The unusual karyotype of Ellobius lutescens (2n = 17,X in males and females) has attracted permanent interest and prompted a series of hypotheses on sex determination in this species since its first description by Matthey (1953). The developing knowledge about the sex chromosomes and sex determination as well as the availability of new cytogenetic and molecular genetic techniques prompted studies to test the compatibility between current hypotheses and new findings and rendered modifications of the hypotheses necessary. After a long period dominated by the question what the sex chromosome constitution of this species might be and where the testis determining factor could be located, the presence of Sry had been eventually excluded and sex determination attributed to a hypothetical mutated gene acting downstream of Sry. An X-chromosomal or autosomal location of this gene can be assessed by cosegregation of sex with X-chromosome markers. Some preliminary results concerning X-chromosome dinucleotide repeat markers are reported. However, these markers were homomorphic in Ellobius lutescens. We now report evidence that Zfy is also missing in Ellobius lutescens and E. tancrei (males and females XX), a finding from which we conclude that the entire Y chromosome has been lost from these species. Perspectives concerning future studies are discussed.

Interstitial deletion 6q16.2q22.2 in a child with ectrodactyly.

A boy of 16 months of age with psychomotor retardation, short stature, microbrachycephaly, triangular face, microphthalmia, palpebral fissures slanted downward, cardiopathy, simian crease on left hand, agenesis of fourth finger on the right hand and of the nail in the second finger on the right one was studied. The karyotype showed a complement of 46, XY, del(6) (q16.2q22.2). The clinical and cytogenetic analysis with other previous cases described in the literature led us to identificate other patients with ectrodactyly. Therefore as other authors we suggest the possible localization of gene(s) that could have involvement with the development of extremities in this segment.

Vitamin D receptor polymorphisms as markers in prostate cancer.

Polymorphisms in the vitamin D receptor (VDR) gene have been analyzed in several studies for an association with prostate cancer (PCA) and odds ratios (OR) > or = 3 have been observed in study populations from North America. We studied three polymorphisms in the VDR gene (poly-A microsatellite, TaqI and FokI RFLPs) in 105 controls and 132 sporadic PCA cases from France and in a collection of families from Germany and France. The polymorphisms near the 3' end of the gene were in linkage disequilibrium with an almost complete coincidence of the short poly-A alleles and t (presence of the restriction site) of the TaqI polymorphism, (contingency tables, P<0.0001). An association was found by logistic regression for the poly-A between PCA and the heterozygous genotype (S/L; S < 17, L > or = 17, OR=0.44, 95% confidence interval, CI=0.198-0.966, P=0.041). OR was lower in patients < or = 70 years old and patients with a Gleason score > or = 6. The Tt genotype of the TaqI RFLP also showed an association with PCA (OR=0.5, CI=0.27-0.92, P=0.026). This association was also stronger for patients < or = 70 years old (OR=0.31, CI=0.15-0.63, P=0.001). The risk alleles were S and t alleles as indicated by the OR of the homozygotes, although these were not significant. The FokI RFLP at the 5' end of the gene did not reveal any association (P>0.7). While some association studies differ between Europe and North America, our present findings with the VDR gene agree with those from North America, indicating a weak but general role of the VDR in PCA susceptibility.