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A Collins

Publications and source records attributed to A Collins.

258 records · Page 15Linked to original sources

Complex segregation analysis in a sample of consecutive newborns with cleft lip with or without cleft palate in Italy.

The mode of inheritance of cleft lip with or without cleft palate (CL/P) has been extensively investigated, but the results are controversial. We report results of complex segregation analysis performed in the families of 636 consecutive newborns with CL/P registered in the northeast Italy and Emilia Romagna congenital malformation registries to test hypotheses regarding CL/P inheritance. The programs POINTER and COMDS have been used. POINTER could not distinguish between alternative genetic models, and only the hypothesis of no familial transmission could be rejected. COMDS results, after inclusion of the severity parameter, rejected the hypotheses of a single major locus and were consistent with the two-locus model with a major dominant locus and at least one modifier locus.

Cleft Lip↗

Nonparametric tests for linkage with dependent sib pairs.

Sib pair tests for linkage to a quantitative trait or affection status are examined by simulation. A sibship of size s contributes only s-1 independent sib pairs but all s(s-1)/2 pairs are needed for an efficient test. Redundancy increases with sibship size. Using simulated data on the null hypothesis of no linkage, we have considered equal and unequal weights. Unequal weights lose power as measured by the equivalent number of observations, and goodness of fit to the theoretical distribution is degraded. The Fisher z(r) test with equally weighted pairs is more reliable than any t(r) test based on conjectured degrees of freedom, but significance levels must be established by simulation if the number of pairs is small or redundancy is large. An approach to parametric analysis through nuisance parameters is discussed.

Alleles↗

Established cardiovascular disease and CVD risk factors in a primary care population of middle-aged Irish men and women.

Contemporary Irish data on the prevalence of major cardiovascular disease (CVD) risk factors are sparse. The primary aims of this study were (1) to estimate the prevalence of major cardiovascular disease risk factors, including Type 2 Diabetes Mellitus, in the general population of men and women between the ages of 50 and 69 years; and (2) to estimate the proportion of individuals in this age group at high absolute risk of cardiovascular disease events on the basis of pre-existing cardiovascular disease or as defined by the Framingham equation. Participants were drawn from the practice lists of 17 general practices in Cork and Kerry using stratified random sampling. A total of 1018 people attended for screening (490 men, 48%) from 1473 who were invited, a response rate of 69.1%. Cardiovascular disease risk factors and glucose intolerance are common in the population of men and women aged between 50 and 69 years. Almost half the participants were overweight and a further quarter met current international criteria for obesity, one of the highest recorded prevalence rates for obesity in a European population sample. Forty per cent of the population reported minimal levels of physical activity and 19% were current cigarette smokers. Approximately half the sample had blood pressure readings consistent with international criteria for the diagnosis of hypertension, but only 38% of these individuals were known to be hypertensive. Eighty per cent of the population sample had a cholesterol concentration in excess of 5 mmol/l. Almost 4% of the population had Type 2 Diabetes Mellitus, of whom 30% were previously undiagnosed. A total of 137 participants (13.5%) had a history or ECG findings consistent with established cardiovascular disease. Of the remaining 881 individuals in the primary prevention population, a total of 20 high-risk individuals (19 male) had a risk of a coronary heart disease event > or = 30% over ten years according to the Framingham risk equation, giving an overall population prevalence of 2.0% (95% CI 1.3 - 3.0). At a risk level > or = 20% over ten years, an additional 91 individuals (8.9%) were identified. Thus a total of 24.4% of the population were at risk either through pre-existing CVD (13.5%) or an estimated 10-year risk exceeding 20% according to the Framingham risk equation (10.9%). Thus a substantial proportion of middle-aged men are at high risk of CVD. The findings emphasise the scale of the CVD epidemic in Ireland and the need for ongoing monitoring of risk factors at the population level and the need to develop preventive strategies at both the clinical and societal level.

Aged↗