| ||Alpha-1-Antitrypsin S/Z Mutations
| ||Alpha-1-Antitrypsin Phenotype
#ExistInterpData>Background Information for A1A (SERPINA1) Enzyme Concentration and 2 Mutations with Reflex to A1A Phenotype:
Characteristics: Coughing, wheezing, chronic obstructive pulmonary disease, emphysema, cirrhosis.
Incidence: 1 in 3000 to 1 in 5000.
Inheritance: Autosomal recessive.
Cause: Mutations in the AAT glycoprotein gene on chromosome 14q31-32.3; homozygosity for the Z allele is the most common cause.
Clinical Sensitivity: 95 percent.
Mutations Detected: S allele (c.791A>T) and Z allele (c.1024G>A).
Methods: Genotyping performed by PCR followed by fluorescent probe melting analysis; AAT protein concentration measured using immunoturbidmetric assay; phenotyping performed by isoelectric focusing. Genotyping and AAT serum protein concentration determination are performed on all specimens. Protein phenotyping is performed on specimens that have AAT serum concentrations of less than 100 mg/dL and are heterozygous for either the S or Z allele by genotyping. In addition, protein phenotyping is performed on specimens that have serum protein concentrations of less than 100 mg/dL and do not contain either S or Z alleles by genotyping. Isoelectric focusing is not performed on specimens that are homozygous for deficiency alleles (ZZ, SZ, or SS) by genotyping.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Mutations other than those targeted in S allele (c.791A>T) and Z allele (c.1024G>A) will not be detected; analytic sensitivity may be compromised by rare primer site mutations.
This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.
See Compliance Statement C: www.aruplab.com/CS
||Alpha-1-antitrypsin serum protein concentration determination and A1A genotyping are performed on all specimens. If two deficiency alleles (ZZ, SZ, or SS) are detected, then no further testing will be added. If the protein concentration is less than 100 mg/dL and only one or no deficiency allele is detected by A1A genotyping, then phenotyping will be added. Additional charges apply.
If reflexed, add 82104
||Alpha 1 Antitrypsin Genotype (Alpha-1-Antitrypsin (SERPINA1) Enzyme Concentration and 2 Mutations with Reflex to Alpha-1-Antitrypsin Phenotype)