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[The value of the Pi system phenotype in alpha 1-antitrypsin deficiency]
Insights
This study highlights Alpha-1-antitrypsin (A1-AT) deficiency in children with liver disease. Detecting Pi system phenotypes is crucial for diagnosing A1-AT deficiency in pediatric liver conditions.
Area of Science:
- Pediatric Hepatology
- Clinical Genetics
- Biochemistry
Context:
- Liver diseases in children encompass a wide spectrum of conditions.
- Alpha-1-antitrypsin (A1-AT) deficiency is a genetic disorder that can manifest with liver disease.
- Early diagnosis is critical for effective management and improved outcomes.
Purpose:
- To investigate the prevalence and diagnostic significance of Alpha-1-antitrypsin (A1-AT) deficiency in children presenting with various liver diseases.
- To evaluate the utility of Pi system phenotyping and liver biopsy findings in identifying A1-AT deficiency.
- To assess the inheritance patterns of the Pi ZZ phenotype within affected families.
Summary:
- A study of 110 children with liver diseases examined Pi system phenotypes to identify Alpha-1-antitrypsin (A1-AT) deficiency.
- Four children (3.6%) with the Pi ZZ phenotype exhibited reduced serum A1-AT levels and characteristic PAS-positive inclusions in hepatocytes.
- Family studies confirmed heterozygous (MZ) parents and normal (MM) siblings, supporting the genetic basis of the deficiency.
Impact:
- This research underscores the importance of routine A1-AT deficiency screening using Pi phenotyping in pediatric liver disease cases.
- Identifying A1-AT deficiency early can lead to timely interventions and potentially alter disease progression.
- The findings contribute to a better understanding of the genetic underpinnings of pediatric liver conditions.
Abstract:
One-hundred-and-ten children between the ages of two months and 14 years with the following liver diseases were studied: 16 with acute viral hepatitis, 8 with persistent chronic hepatitis, 31 with active chronic hepatitis, 5 with hepatic steatosis, 11 with cirrhosis of the liver, 24 with newborn cholestasis, 3 with Wilson's disease, 2 with congenital hepatic fibrosis, 5 with metabolic diseases and 5 due to other causes. These children presented Pi system phenotypes in isoelectric focus using ultrafine polyacrylamide gels according to Kuepper's method, with modifications incorporated to determine Alpha-1-antitrypsin (A1-AT) serum level deficiencies in those presenting the Pi ZZ phenotype, a liver biopsy with P.A.S. coloration on digestion of diastase and a family history of the phenotype. Four (3.6%) of the children with Pi ZZ phenotypes showed a decrease of serum A1-AT and the presence of positive P.A.S. inclusions resistant to diastase in the cytoplasm of hepatocytes. Three had a history of postnatal icterus and the fourth presented hepatomegaly. The phenotypic study of the parents showed their being heterozygous (MZ), while siblings were normal (MM). The importance of the diagnosis of A1-AT deficiency and the diagnostic value of detecting Pi system phenotypes in every case of liver disease in children and adolescents is stressed.