Biomedical subjects

D Ravine

Publications and source records attributed to D Ravine.

45 records · Page 3Linked to original sources

PubMed1994

Evaluation of ultrasonographic diagnostic criteria for autosomal dominant polycystic kidney disease 1.

Although ultrasound is commonly used for screening subjects at risk of polycystic kidney disease 1 (PKD1), there has been no evaluation of ultrasonographic diagnostic criteria. We used DNA linkage among subjects from 128 sibships within 18 PKD1 families as the basis for an assessment of ultrasound sensitivity. Positive and negative predictive values were calculated to allow assessment of different diagnostic cut-off points in previously undiagnosed cases. Currently used criteria (bilateral cysts with at least two in one kidney) provided good sensitivity (88.5% at age 15-29 years and 100% at 30 years and above) but performance could be improved by less stringent criteria in subjects aged 15-29 years and more stringent criteria in older family members, in whom simple renal cysts are frequent. The presence of at least two renal cysts (unilateral or bilateral) in individuals at risk and younger than 30 years may be regarded as sufficient to establish a diagnosis; among those aged 30-59 years, the presence of at least two cysts in each kidney may be required, and among those aged 60 years and above, at least four cysts in each kidney should be required.

Adolescent↗

PubMed1993

Non-specific elevation of immunoreactive trypsinogen in sick infants.

To determine the effect of neonatal illness on immunoreactive trypsinogen (IRT) levels, the IRT values obtained in sick infants transferred to a neonatal intensive care ward were compared with those found in matched controls. IRT levels from dried blood spots collected on day 4-5 of life from 372 sick infants had a mean value of 0.095 log transformed multiples of the median, whilst controls had a mean of -0.013: a highly significant difference. Classification of the sick infants into principal diagnostic categories failed to show any group contributing disproportionately to the observation. In particular, the level of elevation observed in 33 infants with gut abnormalities such as bowel obstruction, duodenal atresia, exomphalos and gastroschisis, in which some degree of pancreatic obstruction might be expected, was not greater than in other hospitalised infants. These data show that sick infants are at increased risk of being identified by an IRT screening programme aimed at detecting infants with cystic fibrosis.

Gastrointestinal Diseases↗

PubMed1993

An ultrasound renal cyst prevalence survey: specificity data for inherited renal cystic diseases.

This study documents the prevalence of simple renal cysts at various ages to produce a table of age-specific specificity values. The specificity of diagnosis for inherited renal cystic conditions depends primarily on the prevalence of simple renal cysts in disease-free subjects. To provide specificity data useful for the ultrasound assessment of individuals at genetic risk of having a renal cyst-forming condition, a prospective ultrasound study was performed. The urinary tract was examined in detail in 729 individuals referred for investigation of symptoms unrelated to the urinary tract and who had normal renal function. The prevalence of individuals with at least one renal cyst was 0% in those aged 15 to 29 years, 1.7% in those aged 30 to 49 years, 11.5% in those aged 50 to 70 years, and 22.1% in those aged 70 years and above. The prevalence of bilateral renal cysts (at least one cyst in each kidney) was 1% in those aged 30 to 49 years, 4% in those aged 50 to 70 years, and 9% in those aged 70 years and above. A table is provided that allows specificity estimates for differing diagnostic criteria together with 95% confidence limits for each estimate. In the younger age groups, bilateral renal cysts, particularly bilateral cysts with one or both kidneys having more than one cyst, are relatively uncommon. A reduced threshold for suspecting inherited renal cystic disease in younger individuals at high genetic risk will continue to have high specificity while improving the sensitivity of ultrasound diagnosis.

Adolescent↗

PubMed1993

Chromosome 4 localization of a second gene for autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is a genetically heterogeneous disorder. A gene defect located on the short arm of chromosome 16 is responsible for the disease in roughly 86% of affected European families. Using highly polymorphic microsatellite DNA markers, we have assigned a second gene for ADPKD to chromosome 4. In eight families with clear evidence against linkage to chromosome 16 markers, linkage analysis with the markers D4S231 and D4S423, demonstrated a multipoint lod score of 22.42.

Adult↗

PubMed1993

Further localization of the gene for nevoid basal cell carcinoma syndrome (NBCCS) in 15 Australasian families: linkage and loss of heterozygosity.

Nevoid basal cell carcinoma syndrome (NBCCS; basal cell nevus syndrome or Gorlin syndrome) is a cancer-predisposition syndrome characterized by multiple basal cell carcinomas (BCCs) and diverse developmental defects. The gene for NBCCS has been mapped to 9q23.1-q31 in North American and European families. In addition, loss of heterozygosity (LOH) for genetic markers in this region has been detected in sporadic BCCs, indicating that the NBCCS gene is probably a tumor-suppressor gene. In this study we have determined that the NBCCS gene is also linked to this region in Australasian pedigrees and that there is no significant evidence of heterogeneity. We have defined the localization of the gene by multipoint and haplotype analysis of 15 families, using four microsatellite markers. LOH at these loci was detected in 50% of sporadic BCCs, a rate that is significantly higher than that in other skin lesions used as controls.

Adult↗

PubMed1992

Phenotype and genotype heterogeneity in autosomal dominant polycystic kidney disease.

It is now clear that mutations of at least two genetic loci can lead to autosomal dominant polycystic kidney disease (ADPKD). We have compared the clinical features of ADPKD caused by mutations at the PKD1 locus (linked to the alpha-globin complex on chromosome 16) with those of disease not linked to the locus (non-PKD1). We identified 18 families (285 affected members) with mutations at PKD1 and 5 families (49 affected individuals) in which involvement of this locus could be dismissed. Non-PKD1 patients lived longer than PKD1 patients (median survival 71.5 vs 56.0 years), had a lower risk of progressing to renal failure (odds ratio 0.35, 95% CI 0.13-0.92), were less likely to have hypertension (odds ratio adjusted for age and family of origin 0.29, 0.11-0.80), were diagnosed at an older age (median 69.1 vs 44.8 years), and had fewer renal cysts at the time of diagnosis. Although most of the PKD1 families were ascertained through clinics treating patients with renal impairment, no non-PKD1 family was identified through this source. Non-PKD1 ADPKD has a much milder phenotype than that linked to PKD1. Partly as a result of this difference in severity, the reported prevalence of this genotype is probably an underestimate.

Adolescent↗

PubMed1991

Perceptions of genetic risk in individuals with a one in two chance of developing autosomal dominant polycystic kidney disease.

OBJECTIVE: To determine the level of understanding of personal genetic risk in people born with a one in two risk of having autosomal dominant polycystic kidney disease (ADPKD). DESIGN: Consenting individuals, contacted through affected family members, were asked standard questions about their knowledge of their own genetic risk. These questions were incorporated into a study investigating the use of DNA diagnostic techniques in ADPKD which was an opportunity to interview a substantial number of Australians at risk of inheriting this condition. SETTING: Interviews were conducted in the individuals' homes, or at the Royal Melbourne Hospital Renal Clinic or the Royal Children's Hospital Genetics Clinic. PATIENTS: Three hundred and eighty-seven individuals aged 15 years or more, born with a one in two risk but who had remained undiagnosed up until the time of study were identified within 46 families. Sixty-six were excluded from the study either because they resided too far away or they declined involvement. The remaining 321 were assessed clinically, 304 of whom were also interviewed about their understanding of their risk of having inherited this condition. RESULTS: Thirty per cent knew their risk at birth was one in two. Nine per cent were unaware that ADPKD was an inherited condition. Forty-one per cent were aware that ADPKD was inherited but had no opinion about their personal risk. Three per cent thought that they had no chance of having the condition, 3% thought that they were definitely affected, 8% considered their risk lay from 1%-49% and 6% thought their risk lay from 51%-99%. CONCLUSION: Within this group of people with a high risk of having an inherited condition with preventable and treatable components, the majority has a poor understanding of their genetic risk.

Adolescent↗

PubMed1991

Treatable complications in undiagnosed cases of autosomal dominant polycystic kidney disease.

In a study to determine the proportion of unrecognised cases and the prevalence of treatable complications of autosomal dominant polycystic kidney disease (ADPKD), 46 probands were identified through genetics and renal clinics in Melbourne, Australia. 321 offspring of the probands who were older than 15 years and had not been previously diagnosed as having ADPKD were identified. 68 (21%) had ultrasound evidence of polycystic kidney disease. Of this previously undiagnosed group, 25 (37%) had one or more treatable complications at the time of diagnosis. The complications included 20 cases of hypertension (diastolic blood pressure 95 mm Hg or above), 7 cases of impaired renal function (serum creatinine 0.12 mmol/l or above), and 4 cases of bacterial urinary tract infection. 8 people had several complications. ADPKD has an important treatable component which is not being treated in a substantial proportion of affected individuals, because the disease is not being diagnosed despite the presence of a positive family history.

Adolescent↗

PubMed1980

Genetic inheritance of susceptibility to tinea imbricata.

Segregation analysis on 228 family pedigrees collected from a Papua New Guinean population provided data that strongly supported a previous report of an autosomal recessive pattern of inheritance of a susceptibility to tinea imbricata. The frequency of the susceptibility gene within the population studied was found to be 0.49 +/- 0.04, calculated on the assumption of an autosomal recessive mode of inheritance. However, in spite of the strong evidence in support of autosomal recessive inheritance, the possibility of autosomal dominant inheritance with reduced penetrance cannot be excluded.

Female↗