More on Cystic Fibrosis

Part 4

Cystic fibrosis also affects the digestive system. In a healthy person, the pancreas produces chemicals (enzymes) which pass into the gut as food leaves the stomach. These enzymes break down the fat. If you have cystic fibrosis, the pancreas does not produce enzymes. Without these enzymes, the fat in food is not properly digested and it is difficult to gain weight. The feces contain an excess of fat and are oily and very smelly (BUPA, 2006). The presentation of unusual feces along with ongoing chest symptoms and failure to thrive in children are the three main factors which physicians will observe for when considering a diagnosis of cystic fibrosis.

The exocrine pancreas is the most profoundly affected gastrointestinal organ in cases of cystic fibrosis. Approximately 85-90% of cystic fibrosis patients suffer from pancreatic insufficiency from birth (Davis et al, 1996). Untreated pancreatic insufficiency can reduce fat absorption to as low as 40-50% and protein absorption is also impaired (Gow et al, 1981). The primary objective in the cystic fibrosis patient is to maintain normal growth into adulthood with the use of pancreatic replacement therapy and other nutritional support. Enzyme preparations are usually taken in capsule form and are available as a powder for young children. The drug is taken with every meal or snack to ensure that the fat and protein absorption is optimized.

Genetic Involvement

Cystic fibrosis is a genetically inherited disease caused by a faulty gene called the cystic fibrosis transmembrane conductance regulator - or CFTR gene. In order to inherit the disease a faulty gene must be passed from both the father and the mother. In cases where only one faulty gene is passed the individual will then be a ‘carrier’ and not have acquired the disease themselves.

When both parents are carriers, with each pregnancy there is a:

• 1 in 4 chance of having a child with cystic fibrosis

• 1 in 2 chance of having a child who is a carrier

• 1 in 4 chance of having an unaffected child

There are several different types of genetic mutation which are associated with different degrees of severity of the disease (BUPA, 2006).

Due to advances in medical science cystic fibrosis can be diagnosed whilst the baby is still in the uterus. The use of chorionic villus sampling (CVS) allows for the detection of the disease before the baby is even born. In cases where both parents are known carriers awareness of whether the unborn infant has the disease is often desirable. The finding of two mutations of the disease confirms that it is present however the finding of only one does not ultimately exclude it. Siblings of a cystic fibrosis patient are at equal risk of having the disease, and often is the case that following diagnosis of one child, parents request that all children be screened, this is usually offered as a standard service to most families anyway.

Research into Cystic Fibrosis

The Cystic Fibrosis Foundation established a Research Development Program Center for research in cystic fibrosis with a five-year, $2 million grant in 1997. It was renewed in 2002 and 2007. The primary goal of the Center is to focus the attention of new and established investigators on multidisciplinary approaches designed to improve the understanding and treatment of cystic fibrosis.

The Center’s research efforts focus on several areas relevant to the understanding and treatment of cystic fibrosis: basic studies of the function, protein interactions, trafficking and processing of the cystic fibrosis gene product, CFTR; understanding the infection-inflammation issues that compromise the function of CF airways; the development of new therapies and diagnostic approaches for treating cystic fibrosis, and participation of Center investigators in clinical studies.