Birth Defects - Genetic - Cystic Fibrosis

Incidence

Cystic Fibrosis is one of the common genetic diseases in the world.

The incidence of the disease is geographically variable. In some areas of the world, it is as high as 1 in 500, while in others it is 1 in 3800. This disease is common among the Ashkenazi or east European Jews and also among people of European descent, one in twenty two of who carry the cystic fibrosis gene.

Causes

It is a disorder that occurs due to mutation in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTCR) gene. This gene codes for a product that influences the production of mucus, digestive juices and sweat. Just a single functioning copy of this gene is enough to prevent the onset of this disease.

But in the cystic fibrosis patients, both the copies of these genes, inherited from each parent are defunct. Two defective genes from each parent are necessary for manifestation of the disorder.

Clinical features

A range of symptoms can be observed among individuals suffering from cystic fibrosis. They may, however, vary in their severity.

• Salty sweat owing to excessive chlorine accumulation
• Serious digestive problems. Malabsorption of vitamins and nutrients
• Highly viscous mucous within the airways of the lungs leading to respiratory problems
• Malfunctioning of the lungs, pancreas, liver, sweat glands and reproductive organs
• Growth retardation might be seen in children with cystic fibrosis
• Poor immuno competence can lead to frequent infections and even pneumonia
• Infertility due to obstructive azoospermia in 95 % of the male patients . Here there is an absence of sperms in the ejaculate due to obstruction of vas deferens

The intensity of the disease is dependent upon the age of the affected individual, the types of infections, and the time and type of treatment that was made available to the individual.

Treatment

No satisfactory treatment is available for the condition. In populations at risk, prenatal diagnosis can be done to detect the condition in the fetus and to terminate the pregnancy if necessary.

A sweat test is carried out as part of the routine newborn screening in some western countries. In such cases treatment can start early.

Oral or intravenous antibiotics may be administered to treat lung or other infections. There really is no cure for cystic fibrosis and most of the affected individuals die young.