CYSTIC FIBROSIS IN HUMANS

Cystic Fibrosis in humans

Cystic Fibrosis in humans

Introduction

First identified in 1938, cystic fibrosis (CF) is the most common inherited life-ending disease found in Caucasians, with an estimated frequency of one in approximately 3,000 live births. Since its initial discovery, scientists have learned that the genetic defect is transmitted as an autosomal recessive trait and that the CF defect impacts a single gene on chromosome 7, named the cystic fibrosis transmembrane regulator (CFTR). Once a uniform death sentence during childhood, because of enhancements in the care of patients with CF, the diagnosis now holds greater promise for a productive and longer life, particularly when care is received through an advanced, evidence-based medicine CF specialty care center. CF patients born in the 1990s are predicted to survive a median of greater than 40 years;this compares favorably to the early mid-20th century, when diagnosis during childhood was once predictive of death within six months.

Discussion

The hallmark of CF is impacted mucus and the list of commonly affected organs includes those in the respiratory tract (nose, sinuses, and lungs); digestive system (intestines, biliary system, and pancreas); and reproductive system.

Although most commonly seen in descendants of European ancestors, CF has been reported in African Americans, as well as in natives of Middle Eastern countries, India, and Pakistan. The frequency of this genetic defect in nonwhites is 1:9,500 Hispanics; 1:11,200 Native Americans; 1:15,000 African Americans; and 1:31,000 Asian Americans.

Symptoms

Respiratory symptoms include cough, shortness of breath, wheezing, and chest pain. When an acute infection occurs, patients may develop fever, muscular pains, fatigue, lack of appetite, and weight loss. Patients may also develop infections and symptoms of sinusitis, bronchitis, and nasal polyps.

Gastrointestinal symptoms may be present at the time of birth. A condition known as meconium ileus (an acute obstruction of the intestines due to thickened secretions) may be present at birth and often requires emergent surgery for correction. CF patients who experience involvement of the pancreas may develop diabetes (usually requiring insulin) and, in addition, experience difficulty digesting proteins and fats. As a result of the protein and fat malabsorption, CF patients commonly report very foul smelling bowel movements that are often described as greasy and difficult to flush.

Vitamin deficiencies are a frequent accompaniment to the intestinal malabsorption seen in CF, and without correction, they may lead to malnutrition, nerve damage, bleeding problems, and thinning of the bones. Other symptoms and conditions that can develop related to the above processes include abdominal pain, constipation, appendicitis, lack of appetite, nausea, vomiting, lack of bowel movements, and gall stones.

Men with CF commonly produce semen without any sperm and, as a result, are not able to naturally father children. This is typically because their vas deferens (the small tubes that connect the testes with the urethra) are congenitally absent. Despite this abnormality, sexual desire and function is typically not altered in men with CF.

Diagnosis And Follow-Up

Males and females are affected equally with CF. It is estimated that 70 percent of patients with CF are diagnosed by ...