Liver involvement in infants with PiSZ phenotype of alpha 1-antitrypsin deficiency

Area of Science:

• Genetics
• Pediatrics
• Hepatology

Background:

• Alpha-1-antitrypsin (AAT) deficiency is a genetic disorder.
• The PiZ allele is associated with severe AAT deficiency and liver disease.
• The PiSZ phenotype represents a moderate AAT deficiency.

Purpose of the Study:

• To investigate the clinical and biochemical manifestations of the PiSZ phenotype in newborns.
• To assess liver function and identify any signs of neonatal cholestasis in PiSZ infants.

Main Methods:

• Newborn screening for protease inhibitor (Pi) phenotype.
• Clinical and biochemical follow-up of PiSZ infants at 2, 5, and 12 months.
• Liver biopsy in one case with persistent abnormal liver enzymes.

Main Results:

• 14 PiSZ infants were identified from 19,432 newborns.
• Three infants showed transient hepatic dysfunction at 2 and 5 months.
• All PiSZ infants had normal liver function tests by 12 months, with no signs of neonatal cholestasis.

Conclusions:

• The PiSZ phenotype in newborns is associated with transient, mild liver dysfunction.
• PiSZ infants do not typically present with neonatal cholestasis.
• Liver involvement in PiSZ phenotype is similar to PiMZ but with AAT levels like PiZZ.