Urea cycle disorders in India: clinical course, biochemical and genetic investigations, and prenatal testing.

BACKGROUND: Urea cycle disorders (UCDs) are inherited metabolic disorders that present with hyperammonemia, and cause significant mortality and morbidity in infants and children. These disorders are not well reported in the Indian population, due to lack of a thorough study of the clinical and molecular profile. RESULTS: We present data from two major metabolic centres in India, including 123 cases of various UCDs. The majority of them (72/123, 58%) presented in the neonatal period (before 30 days of age) with 88% on or before day 7 of life (classical presentation), and had a high mortality (64/72, 88%). Citrullinemia type 1 was the most common UCD, observed in 61/123 patients. Ornithine transcarbamylase (OTC) deficiency was the next most common, seen in 24 cases. Argininosuccinic aciduria was diagnosed in 20 cases. Deficiencies of arginase, N-acetylglutamate synthase, carbamoyl phosphate synthetase, citrin, and lysinuric protein intolerance were also observed. Molecular genetic analysis revealed two common ASS1 mutations: c.470G > A (p.Arg157His) and c.1168G > A (p.Gly390Arg) (36 of 55 tested patients). In addition, few recurrent point mutations in ASL gene, and a deletion of the whole OTC gene were also noted. A total of 24 novel mutations were observed in the various genes studied. We observed a poor clinical outcome with an overall all time mortality of 63% (70/110 cases with a known follow-up), and disability in 70% (28/40) among the survivors. Prenatal diagnosis was performed in 30 pregnancies in 25 families, including one pre-implantation genetic diagnosis. CONCLUSIONS: We report the occurrence of UCDs in India and the spectrum that may be different from the rest of the world. Citrullinemia type 1 was the most common UCD observed in the cohort. Increasing awareness amongst clinicians will improve outcomes through early diagnosis and timely treatment. Genetic diagnosis in the proband will enable prenatal/pre-implantation diagnosis in subsequent pregnancies.

Soluble levels of cell adhesion molecules (CAMs) in coronary artery disease.

AIMS: To analyze soluble levels ofcell adhesion molecules (CAM) such as Intercellular CAM (ICAM), vascular CAM (VCAM-1), platelet endothelial CAM (PECAM-1), Endothelial (E)-selectin, and Platelet (P)-selectin in coronary artery disease patients and correlate with degree of severity of the disease. METHODS: Study population included patients who suffered myocardial infarction at presentation (N=49) and those with unstable angina (N=79) and stable angina (N=14). Soluble levels of CAMs were measured by ELISA. RESULTS: At acute event in AMI patients, there was significant rise of soluble (s) E-selectin (4.5 fold, P = 0.001), sVCAM-1 (65.6%, p = 0.001), sPECAM-1 (46.2%, p = 0.02), sP-selectin (42.7%, p = 0.001) and sICAM-1 (20.1%, p = 0.003) as compared to controls. In unstable angina group as compared to AMI there was significant decrease in the levels observed in, sE-selectin (62.7%, p = 0.001), sPECAM-1 (47.5%, p = 0.001) as well as sVCAM-1 (17.9%, p = 0.04) and insignificant decrease with respect to sICAM-1 and no change with respect to sP-selectin levels. Stable angina group as compared to unstable angina group demonstrated no significant difference in sCAMs and the trend with AMI group was similar to that seen between unstable angina and AMI group. Significantly elevated levels of sE-selectin, sVCAM-1 and sPECAM-1 at acute event suggest them to be causal molecules as well as markers of plaque destabilization. Levels of sP-selectin in stable angina were similar to that observed in AMI and unstable angina groups suggesting elevated platelet activation in stable angina as well.

Leucine125Valine (Leu125Val) Gene Polymorphism of Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1) and Myocardial Infarction in Indian Population.

Platelet-endothelial cell adhesion molecule-1 (PECAM-1) has role in atherosclerotic plaque development as well as in thrombosis leading to myocardial infarction (MI). Present study was aimed to analyse the association of PECAM-1 Leu125Val gene polymorphism with MI in Indian population. Subjects included healthy individuals as control (N = 116) and MI patients (N = 100) divided into two groups; MI patients at presentation of the acute event (MI-Group-1, N = 46) and patients with recent event of MI stabilized with treatment 4.5 days from their symptoms (MI-Group-2, N = 54). The difference in the distribution of Leu125Val genotype frequencies of controls and patients did not reach statistical significance. However Leu allele frequency (0.57) was more associated with MI patients as compared to control (0.504). sPECAM-1 levels were significantly elevated in patients at acute event of MI (MI-Group-1) by 44.1% (P = 0.009) as compared to controls and by 95.2% (P = 0.001) as compared to stabilized MI patients (MI-Group-2).

Role of matrix metalloproteinases in coronary artery disease.

AIM: Matrix metalloproteinases (MMPs) contribute both in the formation as well as in the destabilization of atherosclerotic plaque. In the present study we analyzed circulating levels of MMP-7 that acts on chondroitin sulphate a proteoglycan that is particularly abundant in atherosclerotic plaque and MMP-8 which acts on Type I collagen, the synthesis and degradation of which is important for stability of the plaque and correlate with the degree of severity of coronary artery disease (CAD). METHODS: Circulating levels of MMP-7 and MMP-8 and tissue inhibitors of MMP (TIMP) -1 and TIMP-2 were analysed by Enzyme Linked ImmunoSorbent Assay (ELISA7rpar;, in patients with acute myocardial infarction (AMI) at presentation (N=48), acute coronary syndrome (ACS) group (N=227rpar; (on treatment) and stable angina group (N=17) (on treatment). RESULTS: There was significant rise in MMP-8 (88.23%, P=0.001), in AMI group which decreased in ACS treated group 7lpar;15.9%, non-significant) as compared to controls. There was increasing trend of MMP-7 in AMI and ACS group and strong correlation with hsCRP. MMP-7 predominated in stable angina group. There was significant decrease in TIMP-2 in AMI group and TIMP-1 and TIMP-2 in ACS and stable angina group as compared to controls. CONCLUSION: Significant increase in MMP-8 and decrease in TIMP-2 during acute stage of AMI suggests MMP-8 and TIMP-2 are markers for vulnerable plaque independent of hsCRP for AMI. MMP-7 was found to be elevated in stable angina patients and was correlated with hsCRP at acute phase of AMI suggesting persistent at all stages of CAD.