The role genetics plays in the disease.
Cystic Fibrosis is a genetic disease characterized by hypochloremia and autosomal recessive inheritance tendencies. CF occurs in 1 in 2500 births, and 1 out of 25 whites carry one copy of the specific gene that causes cystic Fibrosis. When one of 2 or more alternative forms of a gene in the DNA sequence is at a genomic location with embryos inheriting two alleles, one from each parent, the individual is homozygous (having identical genome markers found at the same place on the chromosome). . (McCance & Huether, 2019
Homozygous individuals must have a recessive allele to deliver the disease. (National Human Genome Research Institute, 2023) These genes or alleles are classified as normal, wild-type, abnormal, or mutant. If the allele is different, defined as heterozygous, or has two versions of the genomic marker. (Dutra, Ph.D., 2023) The CF gene encodes a protein product that forms chloride channels in the membranes of specialized epithelial cells.
Defective transport of chloride ions leads to a salt imbalance, resulting in secretions of abnormally thick, dehydrated mucus. Some digestive organs, particularly the pancreas, become obstructed, causing malnutrition, and the lungs become clogged with mucus making them highly susceptible to bacterial infections (Pseudomonas). With the progression of the disease, lung disease and heart failure develop, and by age 40, death is expected. Consanguinity or two individuals from the same bloodline (second cousins or closer) becoming pregnant with both carrying the same recessive genes, contributing to the inheritance of CF. (Dutra, Ph.D., 2023, Chapter four)
Why is the patient presenting with the specific symptoms described?
The symptoms: of crying after eating, not gaining weight, having a swollen belly, and skin that tastes like salt are consistent with CF. Presenting due to the baby’s disease progresses. Newborns can and may be asymptomatic, and with age, symptoms develop. CF affects the pancreas and liver, resulting in pancreatic insufficiency leading to malabsorption and malnutrition. Babies with CF can be born with intestinal obstruction (Meconium ileus). The baby is eating, but his body is not metabolizing the nutrients from his food. The baby cannot digest the food, so the food does not move through the GI tract resulting in abdominal swelling. The baby cries after he eats due to the discomfort and pain accompanying his stomach filling and the food being unable to move through the GI tract. Other symptoms reported are swelling in the rectum that can create an intestinal blockage and an inflated colon. (Egan MD et al., n.d.) As a mutated gene, the CFTR modifies the protein that helps transport sodium across the cell membrane. This action results in losing more sodium through sweating and affects how sodium and water move through channels in the body.
CF patients may require specialized vitamins A, D, E, and K due to the inability to metabolize these vitamins, thus creating greater gastrointestinal developments.
The mother reported that her other son had had multiple episodes of chest congestion and pneumonia, symptoms of CF also. This is a clue that the mother was familiar with CF. Cystic Fibrosis creates thickened mucous, allowing mucous buildup within the respiratory tract, resulting in bronchiectasis and infections. Impaired bronchioles/ damaged airways cannot move the mucus up and out of the body.
CF is the most diagnosed genetic disorder presenting symptoms of advancing obstructive lung disease, sinusitis, exocrine pancreatic insufficiency leading to malabsorption and malnutrition, liver and pancreatic dysfunction, and male infertility. Lung infections, breathing problems, wheezing and prolonged coughing, salty-tasting skin and sweat, nose or sinuses (polyps) growth, swelling in the rectum and rectal prolapse, and clubbing of toes or fingers. (Egan MD et al., n.d.)
The physiologic response to the stimulus presented in the scenario and why you think this response occurred.
The physiological response to the stimulus presented resulted from the infant born receiving the recessive gene pattern for Cystic Fibrosis (CF) development from his parents. The child eating is experiencing abdominal pain after eating and therefore cries. The mother offers that she also has a 23-month-old son experiencing symptoms of CF, chest congestion, and pneumonia and has received some information related to CF. the mother is now questioning what CF is and whether she should have any more children. The mother has some knowledge of CF, a hereditary disease. (Dickinson MD, MPH & Collaco, MD, Ph.D., 2021)
The cells that are involved in this process.
CF originates from a specific mutation of the recessive gene pattern, a mutation. They are establishing what specific CF mutation resulted in the disease development. CF results from a misfolded or improperly functioning protein called the Cystic Fibrosis conductance regulator (CFTR). CFTR works in the membrane of the epithelial cells of organs throughout the body as a chloride ion channel. This channel allows chloride to move in and out of the body. The movement of the chloride across the membrane attracts sodium ions across the cell membrane, followed by a subsequent follow of water to the cell’s exterior. The chloride and sodium exchange is the process of hydration and thins mucous. In CF, the dysfunctioning CFTR channel inhibits the water flow, leaving the mucous thickened and without sufficient water, making it difficult for the mucous to move with ciliary clearance. The thickened mucous buildup creates a perfect atmosphere for bacterial growth and the breakdown of normal respiratory functions. The thickened mucous also creates problems in organs such as the sinuses, liver, pancreas, intestines, and male reproductive tract. (Stephen [Shannon], 2015)
How would another characteristic (e.g., gender, genetics) change your response?
CF, an auto-recessive inherited disease, affects males and females equally proportionately. Other factors occur within closely related parents, have a very high probability of having a CF offspring, seen in siblings but not the parents, and one-fourth of the children of parents that are CF carriers will be affected. Questioning the parent’s biological relationship could offer some valuable information. To answer the mother’s question if she should have more children, I recommend genomic testing before conceiving to make an informed decision.
References
Dickinson MD, MPH, K. M., & Collaco, MD, Ph.D., J. M. (2021). Cystic Fibrosis. Pediatrics in Review, 42(2). Retrieved February 26, 2023, from https://pubmed.ncbi.nlm.nih.gov/33526571/Links to an external site.
Dutra, Ph.D., A. (2023). HETEROZYGOUS (Talking Glossary of Genomic and Genetic Terms) [Heterozygous]. National Human Genome Research Institute. Retrieved February 26, 2023, from https://www.genome.gov/genetics-glossary/heterozygousLinks to an external site.
Egan MD, M., Koff MD, J., & Britto-Leon MD, C. (n.d.). Cystic Fibrosis in Children. Yale Medicine. Retrieved February 26, 2023, from https://www.yalemedicine.org/conditions/cystic-fibrosis-in-children#:~:text=In%20addition%20to%20losing%20more%20salt%20through%20sweat,kissing%20their%20babies%2C%20that%20their%20skin%20tastes%20salty.%29Links to an external site.
McCance, K., & Huether, S. (2019). Pathophysiology: The biologic basis for disease in adults and children (8th ed.). Louis, MO: Mosby Elsevier.
National Human Genome Research Institute. (2023). ALLELE (Talking Glossary of Genomic and Genetic Terms) [Allele]. Retrieved February 26, 2023, from https://www.genome.gov/genetics-glossary/AlleleLinks to an external site.
Stephen. (2015). The Cellular Mechanism of CF: The Basics. Cystic Fibrosis News Today.