תוצאת חיפוש

ACE Gene Polymorphism in a Diabetic Cohort and Diabetic Nephropathy

Orna Levinson, Shmuel Oren, Chana Yagil, Marina Sapojnikov, Alexander Wechsler, Rosanna Bloch, Yoram Yagil

Laboratory for Molecular Medicine, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba and Barzilai Medical Center, Ashkelon

The renin-angiotensin system is thought to play an important role in the pathophysiology of kidney disease in diabetes. Previous studies have shown a possible association between the D allele of the angiotensin converting enzyme (ACE) gene, known to be associated with higher circulating levels of ACE, and increased risk of developing nephropathy in NIDDM. The present study investigated the distribution of ACE gene genotypes in the general population and patients with NIDDM, the association between the D allele and diabetic nephropathy, and the association between the ACE genotype and involvement of other target organs in NIDDM. The ACE genotype (insertion/deletion I/D) was determined in all subjects, subsequently divided into 3 groups based on their polymorphism (DD, DI and II). The presence of nephropathy was defined by an albumin-creatinine ratio of 30 mg/g or greater (mean of 2 first morning urine samples).

In the general population most had the D allele (DD or ID) and a minority the II genotype. There was no association between genotype and hypertension, ischemic heart disease, hyperlipidemia, and cerebrovascular or peripheral vascular disease. In diabetics the genotype distribution was not different from that in the general population. Within the diabetic group, there was no association between genotype and hypertension, hyperlipidemia, duration of diabetes, or HbA1C levels. Nephropathy, found in 81 of the 156 with NIDDM, was not associated with genotype. Diabetic nephropathy was not associated with retinopathy, neuropathy, or ischemic heart, cerebrovascular or peripheral vascular disease. We conclude that in the population sampled, there was no association between the D allele of the ACE gene and the risk of developing nephropathy in NIDDM.

Familial Adenomatous Polyposis: Establishing a Registry and Genetic and Molecular Analysis

R. Shomrat, R. Bruchim, Y. Galanty, Z. Samuel, C. Legum, M. Rabau, P. Rozen

Genetic Institute and Depts. of Gastroenterology and Surgery, Tel Aviv Medical Center and Sackler Faculty of Medicine, Tel Aviv University

Familial adenomatous polyposis (FAP), a dominantly inherited disease, is caused by a mutation in the adenomatous polyposis coli gene in chromosome 5q21. The gene has 15 exons, a physical length of 10 Kb and an open reading frame of 8.5 Kb. Exon 15 codes 66% of the mRNA and has a mutation cluster region which accounts for over 50% of mutations. The disease usually leads to the appearance of hundreds of adenomatous polyps in the transverse and descending colon between puberty and age 20 years and to colon cancer before the age of 40. Early detection is essential to prevent the development of metastasizing cancer. Since 1994 we have recruited 23 families for genetic counseling. DNA was obtained from 19 unrelated FAP patients and 219 high risk relatives in 19 unrelated families following confirmation of the diagnosis. In addition to linkage studies, direct mutational analysis was performed using the protein truncation test for most of exon 15 and single strand conformation polymorphism analysis for the other exons. These exons account for most of the mutations identified to date. Of 19 unrelated probands, 14 had detectable mutations. Exon 15 accounted for 6 families, exons 5, 7 and 14 for 1 each, exon 9 for 3, and exon 8 for 2. Combined mutational and linkage analysis identified 18 presymptomatic carriers who received genetic and clinical counseling. Our FAP patients did not differ significantly from those of larger studies in other countries with regard to the distribution of the mutations, gender and genotype-phenotype correlation, or ethnic distribution.