Chromosome 7 and Cystic Fibrosis

Cystic fibrosis is one of the most common genetic disorders. The genes on each chromosome control specific functions of the human body. The gene on chromosome 7 produces a protein called cystic fibrosis transmembrane regulator. Mutation in the DNA level of chromosome 7 leads to the absence of this protein which leads to cystic fibrosis.

Cystic fibrosis is a recessive disease. It means that both copies of the gene must be defective. An affected person will have abnormal cystic fibrosis transmembrane regulator gene on each chromosome 7. Therefore both biological parents must have an abnormal gene. One abnormal copy is inherited from each parent. A person with one normal gene and one abnormal gene is called a cystic fibrosis carrier. Cystic fibrosis carriers do not show any symptoms but they may pass the abnormal gene to their children. Therefore the parents can be either cystic fibrosis carriers or affected themselves.

Cystic fibrosis affects the production and function of cystic fibrosis transmembrane regulator. This disturbs the chloride transfer across cell membranes. As a result, chloride irons build up in the cells of the lungs and other organs. Water stays inside the cells to dilute the chloride and the normal secretions of the organs become thick. Mucus in the exocrine glands becomes thick and sticky. This results in blocks in the pancreas, lungs, liver and other glands. This block leads to cyst formation in glands. This results in cystic fibrosis. Cystic fibrosis causes frequent respiratory infections.

Diagnosis of cystic fibrosis is confirmed by a sweat test or DNA testing. Cystic fibrosis causes the sweat glands to secrete excessive salt. The most common symptoms of cystic fibrosis are coughing and chronic breathing difficulties. This causes repeated lung infections. The lungs and the digestive system are more affected by cystic fibrosis. The symptoms of cystic fibrosis include chronic cough, chest infection, small growth in nose, diabetes, weight loss, pancreatitis, and diarrhea. The treatment of cystic fibrosis includes oral or inhaled antibiotics, corticosteroid tablets, dietary vitamins, anti-asthma therapy and medication.