The Clinical Study on Marfan Syndrome

PURPOSE: The aim of this study was to assess the involvement of several organs patients with Marfan syndrome in Korea. Also the clinical features in childhood patients with Marfan syndrome were assessed. METHODS: Thirty-eight cases of Marfan syndrome were enrolled in this study. Clinical evaluations of the musculoskeletal, cardiovascular and occular system were performed in all cases. RESULTS: The musculoskeletal system was involved in 32 cases (84.2%) and occular system in 24 cases (63.1%). Cardiovascular abnormalities were found in 19 cases (50.0%) at initial evaluation. Family history was involved in 21 cases (55.2%). Ectopia lentis was found in 17 cases (70.8%). Severe myopia and iris abnormalities were also present in 14 cases (58.2%). The ascending aorta was dilated in 13 cases (34.2%). Emergency operation was performed in 3 cases (7.9%) because of a dissecting aorta. Mitral regurgitation and prolapse were found in 29 cases (76.4%) and other valve insufficiency was accompainied in 5 cases (13.1%). Of the 38 cases, 29 patients (79.3%) were less than 15 years of age and their major manifestations were occular problems in 23 cases (79.3%), and family history in 17 cases (58.6%). In one infant, severe heart failure was the predominant clinical feature. CONCLUSION: The clinical features of Korean patients with Marfan syndrome were summarized in this report. Heart failure was the main manifestaton in infantile Marfan syndrome. Early treatment with beta-blocker and valvular replacement can prevent fatality, i.e. aortic dissection, in this disease, concern and management should be advocated in the early detection of Marfan syndrome.

A study of trinucleotide repeat expansions in myotonic dystrophy

PURPOSE: The trinucleotide repeat expansion in the 3' untanslated resion of the gene is known to be the cause of myotonic dystrophy which is one of most common neurodegenerative disorder manifested by myotonia, cataract, mental retardation and even respiratory distress in neonates. The hereditary pattern of myotonic dystrophy shows more severe symptoms and shows earlier onset with successive generations and congenital cases, the most severe form of myotonic dystrophy,. Occurs by maternal transmission. This genetic transmission mode does not follow Mendelian genetic trait. To find the molecular genetic abnormalities of Korean myotonic dystrophy patients, we investigated the general distribution of myotonic dystrophy alleles and compared the results with referred patients. METHODS: During an 8 month study, from June 1995 to February 1996, 5 patients were referred with presumed diagnosis of myotonicdystrophy. Among these patients, four cases were confirmed to have the disease by clinical and electrophysiological findings. We included family members of the studied probands and 50 normal blood donor DNAs were included as controls. The DNAs of the enrolled cases were evaluated by Southern blot. Subsequently, copy numbers of the repeats were determined using PCR amplification. RESULTS: (1) Two peaks were found in the distribution of trinucleotide repeats in the normal Korean population. One peak had 5 copies and the other had 11 to 13 copies. The highest number of copies was 27. (2) Of the referred cases, 4 pedigrees showed typical expanded repeats. (3) The minimum expanded copy number was 55 and we were able to detect the expanded band only by PCR in 2 cases. In other cases, expaded bands were visible by Southern blotting. (4) There were trend of earlier onset of the disease, progressive worsening symptoms and larger expanded bands with successive generations. CONCLUSION: We established the methodology for myotonic dystrophy DNA diagnosis using Southern blot and PCR amplification based on the normal Korean allele distribution. These methods might be useful in genetic counselling and detection of minimally affected myotonic dystrophy patients.

The Molecular Genetic Study Using Automatic Sequence Analyzer on the Steroidogenic Acute Relulatory Protein(StAR) Gene / 대한소아내분비학회지

PURPOSE:The lesion of Congenital Lipoid Adrenal Hyperplasia has been suggested to be in the 1st step of steroidogenesis of conversion of cholesterol to pregnenolone by P450scc. In 1995, however, the molecular defect of this disease has been located in the transport of cholesterol into mitochondria due to defective regulatory protein called Steroidogenic Acute Regulatory Protein(StAR), while the enzyme P450scc itself is normal. This genetic study using automatic sequence analyzer aimed at elucidating the molecular defect in the StAR gene of the two patients. METHODS:This study was performed on the two patients of Congenital Lipoid Adrenal Hyperplasia. Both children were phenotypically females. However, one turned out to have a karyotype of 46, XY, the other 46, XX. Genomic DNAs were extracted from their peripheral blood. We amplified the last exon, hot spot, of the StAR gene using 1 set of primer, S4, 5'-CCT GGC AGC CTG TTT GTG ATA G-3' AS4, 5'-CCT CAT GTC ATA GCT AAT CAG TG-3'. Subsequently, one PCR product have been directly sequenced by dideoxy termination method, and also the other products(patient's and her father's) have been sequenced by automatic sequence analyzer. RESULTS:The mutation was identified in the last exon of the StAR gene, substituting T for A at codon 258, replacing glutamine by stop codon in the two unrelated Korean patients with congenital lipoid adrenal hyperplasia. One patient were found to be homozygote, but the other to be heterozygote for the mutation. CONCLUSIONS:These results indicate that Korean children with congenital lipoid adrenal hyperplasia may be genetically identical as in Japanese. But, we discovered that the hot spot, codon 258, are not always homozygote. We want to emphasize the different point, and to say that we did experiece the automatic sequence analyzer successfully.