Familial hypercholesterolemia with "normal" cholesterol in obligate heterozygotes.

We have investigated the family of a 15-year-old proposita with a homozygous, receptor-defective, familial hypercholesterolemia and found that her consanguineous, obligate heterozygous parents have "normal" cholesterol levels and a family history of unusual longevity. Documentation of paternity and the presence of the heterozygous biochemical disorder in the parents is firm. The implications are that, at least in this family, relatively low serum cholesterol and high levels of HDL cholesterol are protective against the risks associated with having a mutant allele for heterozygous familial hypercholesterolemia.

Genetic--epidemiologic study of early-onset ischemic heart disease.

A genetic-epidemiologic study was undertaken of a white Colorado population of 207 patients who had a myocardial infarction before age 55 years. Nineteen independent variables were compared between the 207 cases and 621 controls, matched 3:1. The highest risk ratios were associated with a positive family history for ischemic heart disease (IHD). The heritability of IHD was 63% when families with the monogenic forms of hyperlipoproteinemia were included, and 56% when they were excluded. A risk index was developed that incorporates family history into a data base of risk factors, which can be readily assessed by the clinician obtaining a screening history, physical and standard laboratory tests. A scale of 0-10 was devised and the predictive value of the index was tested against another data set. The efficiency of the index was maximal at a screening level of 5. This study suggests that it is logistically feasible to seek patients at high risk for intensive management in a clinical setting (high-risk strategy) using risk indices similar to the one developed for this study, which emphasize the very important familial component to IHD.

Echocardiography in Marfan's syndrome.

Echocardiographic examinations were performed in 26 patients with clinical evidence of Marfan's syndrome. Twelve patients were demonstrated to have isolated dysfunction of the mitral valvular apparatus of varying severity. Four patients demonstrated involvement of the aortic root as well as mitral valvular abnormalities, and six patients had problems involving the aortic root only. Four patients had no demonstrable cardiac abnormalities. Therapeutic decisions which could previously have been made with confidence only on the basis of cardiac catheterization with angiocardiographic studies were made by ultrasonic evaluation.

Echocardiographic studies of left ventricular disease in Ullrich-Noonan syndrome.

Echocardiography has been used for cardiovascular evaluation of individuals and families with Ullrich-Noonan syndrome. Previously undiagnosed left ventricular disease has been found as a discrete lesion or in association with other cardiac abnormalities. This raises the estimated frequency of heart disease in the Ullrich-Noonan syndrome to about 50%. Since left ventricular disease in this syndrome may not be entirely typical of asymmetric septal hypertrophy, caution should be exercised in the echocardiographic diagnosis. To date, one notable difference between the echocardiograms in these patients and other patients with asymmetric septal hypertrophy is the absence of systolic anterior motion of the mitral valve. Since the most common cardiac lesion the the Ullrich-Noonan syndrome is pulmonary stenosis, the potential for septal thickening produced by severe pulmonary stenosis must also be taken into account.

Echocardiography in aortic root dissection and dilatation.

Six patients with aortic root dissection proved by angiography, surgery or autopsy, and six patients with aortic root dilatation were studied by echocardiography. Echocardiography was diagnostic in five or six patients with dissection and suggestive in the sixth, disclosing anterior and posterior dissection in three, anterior dissection in one and posterior dissection in one. The recording of a double echo in the aorta was the diagnostic feature. Angiography was diagnostic in four of the six patients, yielded a false negative result in one and was not performed in one. Six patients with dilatation had an enlarged aortic root by echocardiography. Left ventricular size, stroke volume, ejection fraction, aortic regurgitant flow and velocity of circumferential fiber shortening were calculated in 11 patients. Echocardiography was extremely helpful in the diagnosis, management and follow-up in patients with aortic dissection or dilatation.