Post Type Archives: Topics

The osmotic fragility test (OFT) is performed to measure erythrocyte resistance to hemolysis in varying levels of serial dilution of a saline solution/ hypotonic solution. When cells are exposed to a hypotonic environment, water enters the cell and causes swelling and cell lysis. The osmotic lysis of erythrocytes depends upon surface area to volume ratio […]

Hereditary spherocytosis (HS) is the most common inherited red cell membrane disorder causing chronic hemolytic anemia. This defect lead to the formation of spherocytes, which are nondeformable cells. Pathogenesis It is commonly inherited in autosomal dominant pattern. It caused by a deficiency in red blood cell membrane proteins spectrin, ankyrin, or Band 3.1. These are […]

Inflammatory bowel disease is a chronic relapsing inflammatory disorder of intestine. It includes two major forms, Crohn’s disease and ulcerative colitis. Although the exact etiology of IBD is unknown, it involves a complex interaction between the genetic, environmental or microbial factors and the immune responses. Following are major factors associated with Inflammatory Bowel Disease- Genetic […]

Tetralogy of Fallot is a congenital cardiac defect caused by anterosuperior displacement of the infundibular septum, characterized by four defects occurring together- Right ventricular outflow tract obstruction (subpulmonic stenosis) Ventricular septal defect (VSD) Overriding of the VSD by the aorta Right ventricular hypertrophy (RVH) Pathophysiology Conotruncal abnormality from failure of neural crest cells to migrate. […]

DiGeorge syndrome arises because of a microdeletion of chromosome 22q11.2. This deletion of genetic material leads to a developmental defect that involves the third and fourth pharyngeal pouches. Hypoplasia of the thymus and parathyroid glands, aortic arch as well as facial malformations and learning difficulties are most common abnormalities seen in such cases. Patients have […]

Marfan syndrome is an autosomal dominant disorder causing defect in an extracellular glycoprotein called fibrillin-1. Fibrillin is encoded by the FBN1 gene on chromosome 15.   Pathogenesis Fibrillin is secreted by fibroblasts and is the major component of microfibrils. Microfibrils serve as scaffolding for the deposition of tropoelastin, an integral component of elastic fibers. Microfibrils […]

Sheehan’s syndrome is postpartum hypopituitarism caused by necrosis of the pituitary gland. It is usually the result of severe hypotension or shock caused by massive hemorrhage during or after delivery. Risk factors Increased chance of severe blood loss, at the time of childbirth is the most likely cause. Following are most associated risk factors- Abruptio […]

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy affecting hepatocytes. … … Risk factors HCC is a prototypical inflammation-associated cancer, and inflammation causes immune microenvironment and oxidative stress to Induce DNA damage which plays pivotal roles in inducing mutations. Cirrhosis (most common cause) Chronic hepatitis B infection Chronic hepatitis C infection Alcohol abuse […]

Osteogenesis Imperfecta is a hereditary connective tissue disorder with fragile bones due to decrease in the amount of normal Type I collagen. There is severe reduction in bone density that makes bone brittle, recurrent fractures with minimal trauma is very characteristic feature. Pathogenesis Most common form is autosomal dominant. The mutation compromise triple helix folding, […]

Ehlers-Danlos Syndrome is connective tissue disorder involving collagen synthesis and structure. There are multiple types of EDS, based on Severity of skin and joint involvement Mode of inheritance Type of collagen affected  Clinical manifestation Joint hypermobility Skin hyper extensibility Vascular fragility Organ rupture Types (below are most common types) Classical type – it involves collagen […]