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Biomedical subjects

D Schorderet

Publications and source records attributed to D Schorderet.

17 recordsLinked to original sources

Evanescent white linear flecks and posterior microphthalmos: new features of a recently established disease.

BACKGROUND: Posterior microphthalmos is a rare autosomal recessive condition with normal anterior segment and small posterior segment resulting in axial hyperopia and retinal folding. HISTORY AND SIGNS: The proband from a consanguineous Turkish family was clinically investigated at 5 months of age and followed for the next 8 years. At five months of age, refraction revealed a severe hyperopia of + 10 diopters in both eyes (OU) with a mean axial length of 16.5 mm. Fundus examination showed a dystrophic maculo-papillar bundle. Multiple whitish deep intraretinal linear lesions sparing the macula were present in the mid-periphery with no preferential orientation. THERAPY AND OUTCOME: By 8 years of age, visual acuity was 20/25 in the right eye (OD) and 20/30 in the left eye (OS) with S + 14 OU. The whitish linear lesions had disappeared and were replaced by retinal pigment epithelium alterations. Optical coherence tomography (OCT) revealed a thickened retina with normal appearance at the site of the linear lesions. CONCLUSIONS: This is the first report of long-term follow-up and OCT findings in this rare ocular developmental abnormality.

Child↗

Neuropathology of a case of dopa-responsive dystonia associated with a new genetic locus, DYT14.

Detailed autopsy findings are reported for a patient with dopa-responsive dystonia genetically related to the dopa-responsive dystonia locus DYT14 on chromosome 14q13. Substantia nigra and locus ceruleus showed a normal abundance of severely hypomelanized dopaminergic neurons and no Lewy body. In the nigra, the reduction of melanin pigment was found to be asymmetric between the two sides and uneven within neurons, and the lateral aspect of the nigra appeared more affected than the medial, in a pattern similar to the neuronal loss in PD. Dopa-responsive dystonia has a unique neuropathologic signature that seems to be independent of its genotype.

Aged↗

Methylation silencing and mutations of the p14ARF and p16INK4a genes in colon cancer.

The INK4a-ARF locus encodes two tumor suppressor proteins involved in cell-cycle regulation, p16INK4a and p14ARF, whose functions are inactivated in many human cancers. The aim of this study was to evaluate p14ARF and p16INK4a gene inactivation and its association with some clinocopathological parameters in colon cancer. The mutational and methylation status of the p14ARF and p16INK4a genes was analyzed in 60 primary colon carcinomas and 8 colon cancer cell lines. We have identified the first two reported mutations affecting exon 1beta of p14ARF in the HCT116 cell line and in one of the primary colon carcinomas. Both mutations occur within the N-terminal region of p14ARF, documented as important for nucleolar localization and interaction with Mdm2. Tumor-specific methylation of the p14ARF and p16INK4a genes was found in 33% and 32% of primary colon carcinomas, respectively. Methylation of the p14ARF was inversely correlated with p53 overexpression (p = 0.02). p14ARF and p16INK4a gene methylation was significantly more frequent in right-sided than in left-sided tumors (p = 0.02). Methylation of the p14ARF gene occurred more frequently in well-differentiated adenocarcinomas (p = 0.005), whereas the p16INK4a gene was more often methylated in poorly differentiated adenocarcinomas (p = 0.002). The present results underline the role of p14ARF and p16INK4a gene inactivation in the development of colon carcinoma. They suggest that the methylation profile of specific genes, in particular p14ARF and p16INK4a, might be related to biologically distinct subsets of colon carcinomas and possibly to different tumorigenic pathways.

Adaptor Proteins, Signal Transducing↗

[Quick prenatal diagnosis using FISH in the analysis of non-cultured amniotic fluid cells].

We report our experience with fluorescence in situ hybridization (FISH) on uncultured amniocytes and standard cytogenetic analysis. The method have been suggested to 259 patients and performed for 199 amniotic fluid samples. Commercially available chromosome-specific DNA probes (Aneurysm) for chromosomes 13, 18, 21, X and Y were used. All full trisomy 18, 21 and monosomy X were detected by FISH analysis with exception of one case of mosaic monosomy X. No false-positive result was observed. The efficiency, practicability and acceptability of the FISH diagnosis are discussed.

Adult↗

A new mutation, 3905insT, accounts for 4.8% of 1173 CF chromosomes in Switzerland and causes a severe phenotype.

We have analysed 1173 cystic fibrosis (CF) chromosomes from Switzerland for eight mutations in the CF transmembrane conductance regulator (CFTR) gene. This permitted the identification of 88.5% of all mutations present. A novel insertion mutation in exon 20 of the CFTR gene, 3905insT, was discovered. This mutation accounted for 4.8% of CFTR gene mutations in Switzerland and has since been identified in other populations of probable Swiss descent. It is associated with a highly variable clinical phenotype but always with pancreatic insufficiency. Haplotype analysis with three intragenic microsatellites in the CFTR gene showed that the mutation is associated with a haplotype rarely identified on other CFTR alleles and, therefore, that the frequency of the mutation in Switzerland is explained by a founder effect of a relatively recent mutation event.

Cystic Fibrosis↗

Linkage of autosomal dominant radial drusen (malattia leventinese) to chromosome 2p16-21.

OBJECTIVE: To identify the chromosomal location of the gene involved in the pathogenesis of autosomal dominant radial drusen (malattia leventinese). PATIENTS: Eighty-six members of four families affected with radial drusen; one family of American origin and three families of Swiss origin. METHODS: Family members were clinically examined for the presence of radial drusen. Affected patients and potentially informative spouses were genotyped with short tandem repeat polymorphisms distributed across the autosomal genome. The clinical and genotypic data were subjected to linkage analysis. RESULTS: Fifty-six patients were found to be clinically affected. Significant linkage was observed between the disease phenotype and markers known to lie on the short arm of chromosome 2. The maximum two-point lod score (Zmax) observed for all four families combined was 10.5 and was obtained with marker D2S378. Multipoint analysis yielded a Zmax of 12, centered on marker D2S378. The lod-1 confidence interval was 8 cM, while the disease interval defined by observed recombinants was 14 cM. CONCLUSIONS: The gene responsible for autosomal dominant radial drusen has been mapped to the short arm of chromosome 2. This is an important step toward actually isolating the disease-causing gene. In addition, this information can be used to evaluate other familial drusen phenotypes such as Doyne's macular dystrophy for a possible allelic relationship.

Adolescent↗

[Familial uveal melanoma].

BACKGROUND: Familial uveal melanoma are rare and a few number of cases has been described in literature until now. An autosomal dominant inheritance was proposed. MATERIAL AND METHOD: From the 2169 patients examined and/or treated in the Jules Gonin Hospital for an uveal melanoma from 1969, we identified 11 patients from 9 families in which at least two members were affected. We compared the clinical data of the familial melanoma with those of the sporadic cases of our collective with the Kruskal-Wallis Tests. The following parameters were studied: age and sex of patients, largest and smallest tumor diameter, height and volume of tumor, distance between tumor and optic nerve and macula, distance of tumor to the equator. Age and sex were also compared with literature. RESULTS: Among the 11 patients, nine were treated with an accelerated proton beam, one with Cobalt60 applicator and one has been enucleated. The median age was 58 years among the probands and 54.6 years among the sporadic cases of the collective. Sex ratio is superposable between both groups: male 45.5%, female 54.5% among the probands and male 48.6%, female 51.4% among the sporadic cases. The comparison between both groups with the Kruskal-Wallis Tests did not show any significant statistical difference. CONCLUSION: An uveal melanoma occurring at least in two members of the same family is not due to chance alone. Genetic factors associated to external factors are probably responsable.

Adolescent↗

Growth in a case of Russell-Silver syndrome treated for hypopituitarism.

The growth characteristics of Russell-Silver syndrome (RSS) include dwarfism of prenatal onset, moderate retardation of bone age and normal postnatal height velocity. We describe a case of hypopituitarism in a girl with typical RSS who suffered from a severe trauma at birth. Signs of hypopituitarism appeared during childhood. Before substitutive treatment, a short course of human growth hormone (hGH) induced a moderate rise in plasma IGF-I levels which was within the range observed in other pituitary dwarfs. Under replacement therapy, catch-up growth was similar to what is observed in other growth hormone deficient children. However, bone age matured much faster than chronological age. This observation appears to be a particular feature of RSS, possibly enhanced by hGH therapy. An improvement of adult height beyond the final height usually observed in RSS children without endocrine disturbances should therefore not be expected from hGH therapy. Growth hormone deficiency and RSS do not appear to be causally related. However, in each child with RSS, a particular attention should be given to a decreased height velocity, a severely delayed bone age as well as a history of major perinatal problems. Should one of these factors be found, a careful evaluation of the hypothalamo-pituitary axis ought to be performed with, accordingly, an appropriate substitutive therapy.

Child↗

[Tetralogy of Fallot: long-term evolution following corrective surgery].

To evaluate the immediate and long term results of complete correction of tetralogy of Fallot (TF), we have reviewed the records of 275 children operated on in Geneva between 1972 and end 1984. The average age at operation was 6 7/12 years (range 7 months to 16 years). Postoperative follow-up ranged from 1 year to 12 years (average 3 7/12 years). The survival rate, taking into account immediate postoperative mortality, was 90 +/- 2% after one year, 88 +/- 2% after 5 years and 88 +/- 2% after 11 years for the entire patient group. The total mortality of 9.8% has markedly decreased in recent years (14.5% before and 5.7% after 1978). Mortality is highest within the first 30 days after the operation (20 cases, 7.3%). Mortality was higher after previous palliative surgery (5/51) and for children who had to be reoperated for a residual lesion (4/23). Once the first postoperative year has passed, mortality is low: 2 deaths occurred between 1 and 2 years, and one between 2 and 5 years after the operation. Cardiac catheterization in 218 patients between 2 months and one year after surgery showed severe residual pulmonary stenosis in 4 children which made reoperation necessary; a second operation was needed for a large left-to-right shunt in 5 cases, and because of a ventricular septal defect with residual pulmonary stenosis in 6 others. Pulmonary insufficiency was noted in 106 cases (38.5%) but only 3 children showed right heart insufficiency. One child underwent pulmonary valve replacement by Björk-Shiley prosthesis. It can be concluded that a child with surgically treated TF has excellent long term survival, and that life threatening complications after the first postoperative year are rare.

Adolescent↗

SYNDROC: microcomputer based differential diagnosis of malformation patterns.

The differential diagnosis of human malformation patterns is difficult because of their great number and low occurrence. To compensate for deficiencies in experience, the authors have developed a microcomputer based differential diagnosis for dysmorphic syndromes. Written in PL/I-80 and using a MDBS III data base containing more than 700 signs and 300 syndromes, the algorithm of SYNDROC, the program's name, is built on three different approaches. An initial differential diagnosis is given by a pseudo-Bayesian method. Its refinement is possible through an heuristic approach, and undiagnosed cases are stored for subsequent Boolean retrieval, thus permitting the recognition of new dysmorphic disorders. The reliability of the program was tested in a retrospective study based on 100 dysmorphic cases. The results showed a 95% agreement between the first two diagnoses suggested by SYNDROC and the diagnosis made by experienced geneticists.

Abnormalities, Multiple↗

[Cri-du-chat syndrome and two other deformed children in a family carrying a pericentric inversion or insertion of chromosome 5].

Chromosomal syndromes may result from extremely small cytogenetic alterations, involving as little as one chromosomal sub-band. An example is the cri-du-chat (cat cry) syndrome, in which the critical deletion appears to involve the sub-bands 5p15.1-3. Aside from a sporadic deletion of 5p, the loss of material may result from an interstitial deletion, caused by the malsegregation of a balanced parental translocation, or, in exceptional cases, as the consequence of a sporadic or familial chromosomal inversion which has been modified by unequal crossing-over (recombination aneuploidy). In addition, in certain children with the clinical syndrome (11 of 331 in a recent review) the deletion cannot be proven cytogenetically and is presumed to be submicroscopic. In the case described here, an intrachromosomal rearrangement of chromosome 5--an invper(5)(p15q14 or 15) or an ins(5) (p15q12q12)--is segregating in the maternal family. Three of the four children born to the couple were abnormal. The first boy, affected with cleft lip, pyloric stenosis and inguinal hernias, died at 4 months of age. The second died at 3 weeks with microcephaly and agenesis of the corpus callosum, cleft palate, heart malformation, and sexual ambiguity. A third boy, now 14 years old, is phenotypically normal and has a normal karyotype. The female proband, seen by us at 9 years of age, showed the clinical features of the cri-du-chat syndrome, with severe psychomotor and staturoponderal retardation, facial dysmorphism, congenital heart defect, and the peculiar voice for which she had received the nickname of "kitten". Her karyotype shows the same variation of chromosome 5 present in her mother and grandmother, characterized on G bands by an additional dark band on 5p15. As there is no evidence for a reciprocal translocation in the mother, the most probable explanation is that of a familial inversion or insertion within chromosome 5. This rearrangement, subject to meiotic modifications, could have been responsible for the complex malformations observed in 3 of the 4 children, including our proband who has a clinical diagnosis of the cri-du-chat syndrome.

Abnormalities, Multiple↗

[An example of applied data processing in medicine: medical management in a dialysis center].

An application of computers to haemodialysis units is presented. In fact these centers are characterised by an enormous amount of data which should benefit from computerization, and therefore in the haemodialysis unit of the Cantonal Hospital, Fribourg, a program has been developed to handle medical data. This program, as far as we know the only one of its kind in Switzerland, has already been in use for the last 9 months. Swiftly, surely and simply it allows storage and retrieval of all the administrative and medical data of each patient. Facility of data retrieval, graphic data display and automatic data evaluation has been found to improve clinical management of patients. It also considerably facilitates scientific work. Once the adaptation period is over it permits definite time savings. We are convinced that, after the necessary period of introduction, computers can be of considerable help in medical care.

Computers↗