Specific Genetic Diagnosis Research Articles

Facial clefts in the west of Scotland in the period 1980-1984: epidemiology and genetic diagnoses.

Two hundred and eighty six cases of cleft lip, cleft palate, or both were identified in a study attempting complete ascertainment of babies with facial clefts born to women resident in the west of Scotland in a five year period beginning 1 January 1980. The total birth prevalence (TBP) of these defects over this period was 1.53 per 1000. The TBP for cleft lip with or without cleft palate (CL[P] was 0.74 per 1000 and for cleft palate (CP) was 0.79 per 1000; 26% of CL[P] and 39.5% of CP cases had one or more major congenital anomaly associated with their facial cleft and in over half of these cases a specific genetic or syndrome diagnosis could be made. In comparison to previous European reports this study shows a high incidence of associated abnormalities and a remarkably low ratio of CL[P]:CP cases.

Genetics of Common Diseases of Adulthood: Implications for Prenatal Counseling and Diagnosis

Genetic factors play an important role in the development of many common diseases of adulthood that result in early morbidity and mortality. Prevention of these disorders and their sequelae is best established through early detection and early intervention. Although it may be feasible to screen the entire population for some disorders (e.g., hypertension), this approach would be expensive and impractical for others (e.g., colon cancer). The family history provides an inexpensive and convenient method of identifying families at risk for premature diseases of adulthood. Family screening for a disorder should be recommended if there is increased risk for the disorder among family members, if screening methods are available to detect the condition at an early age or preclinical stage, and if early intervention will alter the course of the disease. For many disorders screening and intervention can prevent the occurrence of clinical disease. The prenatal counseling session affords an ideal setting for identifying families at risk for diseases of adulthood with major genetic components. By reviewing the family history, key family members can be identified and investigated, in order to establish a specific genetic diagnosis. At-risk relatives can then be counseled and screened for the disorder preclinically and premorbidly. The screening and intervention available for a disease depends on the nature of the disorder, our understanding of its physiology and etiology, and our current technology. The disorders discussed earlier are typical of conditions of adulthood that are influenced strongly by genetic factors, especially when they appear in younger adults. Atherosclerosis, colon cancer, and diabetes are complex phenotypes. Each can be caused by single-gene defects, but commonly the genetics are more complex. Empiric data help to establish the risk to an individual in the latter cases. In all three examples, early detection should lead to treatment, which can prevent more serious sequelae: by treating the dyslipidemia, coronary artery disease can be prevented; by removing the benign polyp, malignant cancer can be avoided; and when impaired glucose tolerance is detected, diet and exercise can prevent or delay frank diabetes and its complications. The complete evaluation of individuals at risk for disorders such as those in Table 1 and their families can be a complicated task. Referral to a center experienced in the genetics of common diseases often may be necessary.(ABSTRACT TRUNCATED AT 400 WORDS)

Postprandial adipose tissue lipoprotein lipase activity in primary hypertriglyceridemia

The fasting activity of adipose tissue lipoprotein lipase has been previously reported to be either normal or reduced in subjects with a primary form of hypertriglyceridemia. The postprandial activity of adipose tissue lipoprotein lipase has not been previously reported in these subjects. In subjects with primary hypertriglyceridemia the fasting lipoprotein lipase activity eluted from pieces of adipose tissue by heparin and the enzyme activity present in extracts of acetone-ether tissue powders were similar to the level of enzyme activity found in normal subjects. There also was no difference in the postprandial adipose tissue heparin-elutable lipoprotein lipase activity between these two groups when measured after high carbohydrate feeding. When the subjects with primary hypertriglyceridemia were further subdivided by genetic diagnosis, there was no difference in the level of adipose tissue lipoprotein lipase of subjects with familial hypertriglyceridemia, familial combined hyperlipidemia, or in those in whom no specific genetic diagnosis could be made. The change in lipoprotein lipase activity after feeding was inversely related to the fasting enzyme level in both the normal subjects ( r = −0.58, p < 0.05, n = 12) and the hypertriglyceridemic subjects ( r = −0.92, p < 0.01, n = 11). In the normal subjects, the plasma triglyceride response to feeding correlated inversely with the postprandial change in lipoprotein lipase activity ( r = −0.76, p < 0.02, n = 12). Adipose tissue lipoprotein lipase activity in patients with primary lipoprotein lipase deficiency was markedly reduced in the fasting state and remained essentially zero after feeding. This suggests that a functional role exists for the enzyme activity as measured.