Alpha-1-anti trypsin Genotyping

Alpha-1-antitrypsin (A1AT) deficiency may manifest itself in a range of ways from liver disease in the neonatal period to lung disease in adult life depending on the mutation present (i.e. Z or S mutations). Whilst measurement of A1AT concentrations can be useful as a first line screen for deficiency, as A1AT is an acute phase protein, concentrations can approach the normal reference range in acutely ill subjects. Phenotyping, using isoelectric focusing, allows the mutation to be identified and the screening of siblings or other members of the family, who may be asymptomatic at the time. A1AT genotype analysis is offered as an adjunct to the phenotyping service and for family studies. Homozygosity or heterozygosity for the Z and S mutations can be detected using a real-time Taqman assay. Other variants and null alleles are not detected by this method.
Clinical details: 
Factors affecting results or interpretation: Presence of heparin anticoagulant will inhibit PCR applications. Clotted samples are unsuitable for DNA analysis. Samples must be clearly labelled with the patients first name, surname, D.O.B, hospital number and the date the sample was taken. The details on the sample must correspond to the request form. Unlabelled samples will not be accepted.
Sample type and Volume required: 
Volume of blood anticoagulated with EDTA: Adult and children 4 ml, Infants (0-2 years) 1 ml
Clotted samples are unsuitable for DNA analysis.
Blood Samples in in correct anticoagulant tubes may be rejected.
We accept DNA samples. Please provide at least 1-5µg of purified DNA
For prenatal diagnosis please refer to section for sample requirements.
Turnaround time: 
10 working days. Please note any clinical urgency on the referral form, so samples can be prioritised.
Storage and transport: 
Blood should be stored at 4°C where possible. Send at room temperature by first class post. If possible, please complete the request form attached and send as a hard copy (do not send electronically) with the sample. This will ensure all relevant information is available and will aid us in processing your test.
Time limit for extra tests: 
5 years
Red Cell Centre - Molecular Diagnostics Laboratory
020 3299 1246 / 2265
c/o Central Specimen Reception
Blood Sciences Laboratory
Ground Floor Bessemer Wing
King’s College Hospital
Denmark Hill
London SE5 9RS
Mon-Fri, 9.00am-5.30pm
For clinical advice or interpretation of results, please contact the laboratory in the first instance.

Print as a PDF

Last updated: 29/09/2022