As you work with your preceptor, you learn that she is planning a training session for all new nurses to familiarize them with principles of genetics and genomics using data from a three-generation family pedigree. She asks your help in building a pedigree and genogram to reflect inherited genetic disease processes. You agree to do some reading and describe a genetic disorder and provide a genogram that would indicate how this disorder is transferred over generations. Your preceptor asks you to pick one from this list:

Introduction

In this assignment, we will explore the concept of genetic disorders and their inheritance patterns through the creation of a genogram. A genogram is a visual representation of a family tree that depicts the presence of a particular genetic disorder across multiple generations. To fulfill the request of our preceptor, we will research and describe one genetic disorder and provide a genogram to demonstrate its transmission through generations.

Genetic disorders arise from alterations or mutations in genes, which can affect the structure or functioning of proteins involved in important biological processes. These disorders can be either inherited from parents or can occur sporadically due to new mutations in an individual’s genes.

For this assignment, we will focus on the disorder known as cystic fibrosis (CF). CF is a hereditary disorder that primarily affects the lungs and digestive system. It is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which is responsible for producing a protein that regulates the movement of salt and water in and out of cells.

Description of Cystic Fibrosis

Cystic fibrosis is a relatively common genetic disorder, with an incidence of approximately 1 in every 3,500 newborns worldwide. The severity of symptoms can vary among affected individuals, but generally, CF leads to the production of thick, sticky mucus that clogs the airways and various organs, leading to recurrent respiratory infections, digestive issues, and potential complications in other systems.

The CFTR gene is located on chromosome 7 and is inherited in an autosomal recessive manner. This means that both copies of the CFTR gene need to be mutated for an individual to develop CF. If an individual has only one mutated copy of the gene, they are considered carriers and do not typically exhibit symptoms of the disorder.

Creating the Genogram

To visually represent the inheritance of CF within a family, we can construct a genogram that demonstrates the transmission of the CFTR gene mutations across multiple generations.

First, we will consider an affected individual, denoted by using a filled-in square for males or a filled-in circle for females. In our genogram, we will assume the affected individual is a female. We will also use an open square or circle for unaffected individuals.

Next, we will represent the carriers of the CFTR gene mutations, who do not have symptoms of CF but can pass on the mutations to their offspring. These individuals will be designated by a half-filled square or circle.

Finally, we will indicate unaffected individuals who do not carry the CFTR gene mutations. These individuals will be represented by an open square or circle.

To illustrate the transmission of CF within a family, we can consider a hypothetical scenario. Let’s assume that both parents are carriers of the CFTR gene mutations and have one affected child. They have two other children who are carriers but do not exhibit symptoms of CF.

In this scenario, the genogram would consist of the following elements:

– The affected individual, denoted by a filled-in circle, would be placed at the top of the genogram.
– The parental generation would be represented by two half-filled circles, indicating the carriers of the CFTR gene mutations.
– Two half-filled circles below the parental generation would represent the carrier siblings.
– Finally, open circles in the subsequent generation would symbolize unaffected individuals who do not carry the CFTR gene mutations.

This genogram would visually demonstrate the transmission of CF from carrier parents to their affected child and carrier siblings, while also showing that unaffected individuals do not carry the CFTR gene mutations.

Conclusion

In conclusion, cystic fibrosis is a genetic disorder caused by mutations in the CFTR gene. It is inherited in an autosomal recessive manner, and its transmission can be effectively visualized using genograms. Through the use of a genogram, we can clearly depict the presence of CF in multiple generations and understand the inheritance patterns associated with this disorder. By creating an accurate genogram, nurses can increase their understanding of genetic disorders and explain them to patients and their families, thus facilitating appropriate care and genetic counseling.