Related Experiment Video
Updated: Aug 5, 2026

Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity
Published on: January 6, 2015
Alpha-1-antitrypsin deficiency in childhood
Insights
Alpha-1 antitrypsin (alpha 1AT) deficiency increases children's risk of liver injury and adults' risk of emphysema. Genetic testing can identify susceptible individuals for counseling on environmental toxins.
Area of Science:
- Genetics
- Pulmonology
- Hepatology
Background:
- Alpha-1 antitrypsin (alpha 1AT) deficiency is an inherited disorder with codominant inheritance.
- This deficiency predisposes individuals to liver disease in childhood and emphysema in adulthood.
Observation:
- Pi typing is a reliable method for identifying individuals with alpha 1AT deficiency.
- Amniocentesis is currently not a proven diagnostic technique for detecting homozygous deficiency in utero.
- Predicting the clinical course of homozygous alpha 1AT deficiency is not yet possible, posing challenges for family counseling.
Findings:
- Pi typing can identify susceptible individuals who benefit from counseling on avoiding environmental toxins like smoking and alcohol.
- Liver biopsy may offer prognostic information but is not essential for diagnosis.
- Infants with cholestasis should be evaluated for alpha 1AT deficiency before surgical exploration for bile duct lesions.
Implications:
- Early identification of alpha 1AT deficiency through Pi typing enables targeted counseling and preventative strategies.
- Routine evaluation for alpha 1AT deficiency in infants with cholestasis can prevent unnecessary surgical interventions.
- Further research is needed to develop effective therapies for the underlying defect of alpha 1AT deficiency.
Abstract:
alpha 1AT deficiency predisposes children to liver injury and adults to emphysema. Pi typing has clarified that the inherited deficiency is codominant. Amniocentesis is unproved as a reliable technique in detecting the homozygous deficient patient (another controversial issue). Even if this procedure were to become diagnostic, present knowledge cannot predict the clinical course of each individual born with homozygous alpha 1AT deficiency, therefore confronting the physician and parents with a moral dilemma that neither of us feels comfortable with in regard to family counseling. Presently, we can only educate the family with the current state of the art summarized in this review. The fundamental steps in evaluating a child and the involved family are outlined in Table 2. Steps 1, 2 and 5 should be readily available. Pi typing can specifically identify susceptible individuals who can be counseled concerning work habits and known toxins such as smoking and alcohol. Liver biopsy is not essential for diagnostic purposes but may prove to be prognostic concerning the child's ultimate outcome. More certain is the evidence that no infant should be explored for a bile duct lesion during the early cholestatic period because no surgical lesion will be found. Therefore, all children with infantile cholestasis should be evaluated for alpha 1AT deficiency prior to a laparotomy. Although medical therapy is only supportive at the present time, further research should eventually provide therapeutic approaches to the basic defect.
Related Concept Videos
Breathing
Cystic Fibrosis: Pathogenesis
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation, but...
Cystic Fibrosis: Management
Sinus disease and chronic sinusitis...
Type I Diabetes I: Introduction
Chronic Obstructive Pulmonary Disease I: Introduction
Chronic Obstructive Pulmonary Disease II: Emphysema

