Diagnosis of alpha-1-antitrypsin deficiency by DNA analysis of children with liver disease

• Main Authors: De TOMMASO Adriana Maria Alves, ROSSI Cláudio Lúcio, ESCANHOELA Cecília Amélia Fazzio, SERRA Heliane Guerra, BERTUZZO Carmen Sílvia, HESSEL Gabriel
• Format: Article
• Language: English
• Published: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia (IBEPEGE) 2001-01-01
• Series: Arquivos de Gastroenterologia
• Subjects: Alpha-1-antitrypsin deficiency; Molecular diagnosis; Liver biopsy
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0004-28032001000100012
• ISSN: 0004-2803; 1678-4219

Background - Alpha-1-antitrypsin deficiency is a genetic disorder which is transmitted in a co-dominant, autosomal form. Alpha-1-antitrypsin deficiency affects mainly the lungs and the liver leading, in the latter case, to neonatal cholestasis, chronic hepatitis or cirrhosis. A precise diagnosis of Alpha-1-antitrypsin deficiency may be obtained by biochemical or molecular analysis. Objective - The purpose of this study was to use DNA analysis to examine the presence of an alpha-1-antitrypsin deficiency in 12 children suspected of having this deficiency and who showed laboratory and clinical characteristics of the disease. Patients and Methods - Twelve patients, aged 3 months to 19 years, who had serum alpha-1-antitrypsin levels lower than normal and/or had hepatic disease of undefined etiology were studied. The mutant alleles S and Z of the alpha-1-antitrypsin gene were investigated in the 12 children. Alpha-1-antitrypsin gene organization was analyzed by amplification of genoma through the polymerase chain reaction and digestion with the restriction enzymes Xmnl (S allele) and Taq 1 (Z allele). Results - Seven of the 12 patients had chronic liver disease of undefined etiology and the other five patients had low serum levels of alpha-1-antitrypsin as well as a diagnosis of neonatal cholestasis and/or chronic liver disease of undefined etiology. Five of the 12 patients were homozygous for the Z allele (ZZ) and two had the S allele with another allele (*S) different from Z. Conclusion - These results show that alpha-1-antitrypsin deficiency is relatively frequent in children with chronic hepatic disease of undefined etiology and/or low alpha-1-antitrypsin levels (41.6%). A correct diagnosis is important for effective clinical follow-up and for genetic counseling.