Congenital cataract: An ocular manifestation of classical homocystinuria.

BACKGROUND: Homocystinuria is an autosomal recessive metabolic disorder occurring due to the defects in cystathionine-ß-synthase enzyme. The study was carried out to investigate a Pakistani family presenting bilateral congenital cataract with symptoms of classical homocystinuria at LRBT Free Eye Hospital, Lahore, Pakistan. METHODS: Three affected individuals of the family presented skeletal deformations, intellectual disability, speech delay, and myopia with bilateral congenital cataract. Genetic analysis on DNA samples from affected individuals was done through whole exome sequencing to identify underlying genetic variant causing disease phenotypes in the family. In silico analysis was done to predict the effect of variation on the structure of mutant protein. RESULTS: A missense allelic variant (NM_000071.3: c.253G>A) of the CBS gene was revealed which may affect the catalytic activity of the substituted (NP_000062.1: p.G85R) protein by disrupting the folding of the enzymatic protein. High levels of homocysteine were observed in the plasma of affected individuals. This is the first report of this genetic variant from Pakistan causing homocystinuria and congenital cataract in association. CONCLUSION: This variant was reported first time in association with congenital cataract instead of ectopia lentis. Congenital cataract was developed secondarily in these patients and provided a clue for the early diagnosis of metabolic disorders like homocystinuria to prevent further complications and morbidity.

An update of pathogenic variants in ASPM, WDR62, CDK5RAP2, STIL, CENPJ, and CEP135 underlying autosomal recessive primary microcephaly in 32 consanguineous families from Pakistan.

BACKGROUND: Primary microcephaly (MCPH) is a congenital neurodevelopmental disorder manifesting as small brain and intellectual disability. It underlies isolated reduction of the cerebral cortex that is reminiscent of early hominids which makes it suitable model disease to study the hominin-specific volumetric expansion of brain. Mutations in 25 genes have been reported to cause this disorder. Although majority of these genes were discovered in the Pakistani population, still a significant proportion of these families remains uninvestigated. METHODS: We studied a cohort of 32 MCPH families from different regions of Pakistan. For disease gene identification, genome-wide linkage analysis, Sanger sequencing, gene panel, and whole-exome sequencing were performed. RESULTS: By employing these techniques individually or in combination, we were able to discern relevant disease-causing DNA variants. Collectively, 15 novel mutations were observed in five different MCPH genes; ASPM (10), WDR62 (1), CDK5RAP2 (1), STIL (2), and CEP135 (1). In addition, 16 known mutations were also verified. We reviewed the literature and documented the published mutations in six MCPH genes. Intriguingly, our cohort also revealed a recurrent mutation, c.7782_7783delGA;p.(Lys2595Serfs*6), of ASPM reported worldwide. Drawing from this collective data, we propose two founder mutations, ASPM:c.9557C>G;p.(Ser3186*) and CENPJ:c.18delC;p.(Ser7Profs*2), in the Pakistani population. CONCLUSIONS: We discovered novel DNA variants, impairing the function of genes indispensable to build a proper functioning brain. Our study expands the mutational spectra of known MCPH genes and also provides supporting evidence to the pathogenicity of previously reported mutations. These novel DNA variants will be helpful for the clinicians and geneticists for establishing reliable diagnostic strategies for MCPH families.

Low-molecular-weight heparin in the acute and long-term treatment of deep vein thrombosis.

Low molecular weight heparins (LMWHs) are frequently used during acute treatment of deep vein thrombosis, but their utility for long-term treatment needs to be defined. In this multi-centre trial, 378 patients with acute deep vein thrombosis were randomised to intravenous unfractionated heparin (group A), once daily subcutaneous LMWH (bemiparin) for one week (group B) or once daily bemiparin in a therapeutic dose for one week followed by a maintenance dose for 12 weeks (group C). Fifty-two per cent of patients in group A, 72% of group B and 72% of group C showed venographic reduction in thrombus size assessed objectively on day 14; 20% greater improvement in group B and C indicates not only non-inferiority of bemiparin (p = 0.00003) but also superiority (p = 0.004) compared to UFH. Day 84 venographic or Doppler sonographic recanalisation of the affected veins was demonstrated in 75.3%, 79.8% and 81.5% in groups A, B and C respectively. Mortality, recurrent thromboembolic events and bleeding were similar in the three groups. Both bemiparin regimens were more effective than UFH in reducing thrombus size during the acute phase of treatment. The efficacy in terms of recurrence of venous thromboembolism and safety of Bemiparin is similar to UFH. Bemiparin is also an effective alternative to warfarin for long-term treatment.

Blood coagulation in patients with chronic heart failure: evidence for hypercoagulable state and potential for pharmacological intervention.

Incidence data on thromboembolism in patients with heart failure (which may include stroke, peripheral embolism, pulmonary embolism) are limited but provide a general population range from 1-5 cases per 1000 each year, increasing with age to more than 30 cases per 1000 each year among people aged 75 years or older. However, the incidence of thromboembolism varied depending very much on what was being investigated in each of these studies. Data from subgroup analysis of the larger heart failure trials would seem to support this incidence data, although there is very little true epidemiological data and no randomised, controlled trial has been designed to specifically investigate thromboembolism in patients with heart failure. The pathophysiology of heart failure is complex. There are many well recognised factors which are associated with thrombosis in heart failure patients, such as vascular abnormalities, increased coagulability and impaired blood flow. In the past 50 years many studies have been performed to investigate if oral anticoagulation is of benefit for the prevention of thromboembolism in patients with heart failure. The use of warfarin therapy for heart failure patients has been a controversial subject. Warfarin does have a role to play in patients with myocardial infarction and those with atrial fibrillation. Furthermore, in patients with congestive heart failure secondary to coronary artery disease, warfarin reduces the occurrence of nonfatal myocardial infarction and, therefore, may reduce the chances of progression to heart failure. It has also been shown that warfarin reduces the risk of thromboembolic strokes in patients recovering from myocardial infarction. At present, there is a lack of randomised data, and the incidence of bleeding complications in patients with heart failure has caused a decrease in the use of oral anticoagulants for the prevention of thrombosis. This review summarises the incidence, potential mechanism and therapeutic approaches for management of thromboembolism in heart failure.

Induced ischemia detected by dobutamine stress echocardiography in coronary heart disease patients after myocardial re-vascularization. Experience in a District General Hospital.

Most episodes of myocardial ischemia in patients with known coronary artery disease (CHD) are asymptomatic. Silent myocardial ischemia (SMI) is an important predictor of adverse outcome in patients with proven coronary artery disease. beta-blockers are effective in suppressing ischemia, and improve clinical outcome in patients with coronary artery disease. At present, it is common practice to stop treatment with beta-blockers in clinically asymptomatic patients after coronary artery bypass graft (CABG) and/or myocardial re-vascularization (PTCA/Stent), although the possible presence of SMI/inducible ischemia after myocardial re-vascularization is not known. We examined 56 asymptomatic CHD patients after coronary artery bypass graft (n=36), percutaneous coronary angioplasty PTCA/stent (n=15), or both (n=5); therapy with beta-blockers was stopped in all of them after myocardial revascularization. All these patients underwent a dobutamine stress echocardiography test (DSE test). The DSE test was proposed to these asymptomatic CHD patients to investigate the possible presence of SMI/inducible ischemia after myocardial re-vascularization. All patients had history of myocardial infarction or evidence of mildly impaired left ventricular function at rest as assessed by cardiac catheterization. Abnormal DSE studies occurred in eight of the 56 patients (14%; 95% C.I.: 6-26%). Therapeutic approaches specifically targeted at reducing total ischaemic burden include pharmacologic therapy and myocardial revascularization. On the basis of these data, it can be concluded that asymptomatic CHD patients after myocardial re-vascularization must be re-evaluated to rule out SMI/inducible ischemia that can be treated (e.g. with beta-blockers) reducing cardiovascular morbidity and mortality.

Low molecular weight heparin (bemiparin sodium) and the coagulation profile of patients with heart failure.

BACKGROUND: Congestive heart failure (CHF) is associated with a hypercoagulable state. PATIENTS AND METHODS: A single-center, randomized, double-blind, placebo-controlled trial was performed to test the hypothesis that a prophylactic dose of low molecular weight heparin (bemiparin sodium 3500 IU/daily subcutaneously) will modify a hypercoagulable state in CHF. This study included 100 patients with CHF (New York Heart Association classification II to IV). All patients underwent 3 blood tests, at baseline (before randomization), 24 hours after randomization, and before hospital discharge or within 10 days from randomization. RESULTS: In comparison of baseline bemiparin sodium 3500 IU/daily subcutaneously with after 24 hours, there was a significant decrease in plasma levels of D-dimer (-13.8 ng/mL; P =.01) and prothrombin fragments 1 and 2 (-0.11 nmol/L; P =.01), whereas protein C was significantly increased (+3.5%; P =.03). In comparison of baseline bemiparin sodium 3500 IU/daily subcutaneously with after 4 to 10 days of therapy, there were significantly decreased plasma levels for factor VII:c (-3.0%; P =.01), D-dimer (-44.0 ng/mL; P =.002), and thrombin-antithrombin complex (-0.7 microg/L; P =.0001), whereas protein C was significantly increased (+16.0%; P =.03). On the other hand, in the group of patients treated with placebo after 24 hours, a significant decrease was observed of protein C (-4.0%; P =.04). After 24 hours, the changes from baseline were significantly different for some of the hemostatic factors in comparison of bemiparin sodium 3500 IU/daily and placebo (factor VII:c: -1.7 versus 0.0%; P =.04; D-dimer: -14 versus +24.3 ng/mL; P =.009; prothrombin fragments 1 and 2: -0.11 versus +0.11 nmol/L; P =.01; protein C: +3.5 versus -4.0%; P =.01). Also at discharge, the changes from baseline were different for some of the markers in comparison of bemiparin sodium with placebo (D-dimer: -44 versus 3.8 ng/mL; P =.002; thrombin-antithrombin complex: -0.70 versus +0.14 microg/L; P =.002; protein C: +16.0 versus +0.5%; P =.02). CONCLUSION: Our findings suggest that a hypercoagulable state in heart failure can be modified with bemiparin sodium therapy.