Hereditary Lactase Persistence: LCT 5′ Enhancer Genotyping

Diagnostic Use

Genetic hypolactasia is inherited as an autosomal recessive trait, and is present in ~8% of the NZ caucasian population. A high incidence of genetic hypolactasia is present in people of Pacific Island and/or Maori ethnicity.

This test can be used to eliminate or confirm a genetic cause for lactose sensitivity/intolerance.

Department

Genetics - Molecular Pathology

Delphic Registration Code

MOLP

Constituent Tests

• Genomic DNA Extraction

Synonyms

Adult Hypolactasia
Lactose Intolerance

Turnaround Time

4 weeks

Test Code

7302

Specimen Type

• Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

4.0

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred Sample Volume (ml)

1.0

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

This genetic test needs nucleated cells. Please don’t centrifuge or freeze the EDTA blood tube.
If storing blood tube prior to delivery please refrigerate at 4 degrees (transport still at ambient temperature).

Aliquot Instructions

Sample Type

• Whole Blood

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Additional Referral/Aliquot Information

Please don’t centrifuge or freeze the EDTA blood tube.
If storing blood tube prior to delivery please refrigerate at 4 degrees (transport still at ambient temperature).

Interpretation

Genetic hypolactasia is inherited as an autosomal recessive trait, and is present in some 8% of the NZ caucasian population. The report provided to physicians is sufficiently detailed as to allow clarification of the results provided.

Test Method

The c.-13907 C/T SNP is located 5’ to LCT which is located in intron 13 of the adjacent MCM6 helicase gene on chromosome 2. The 300bp amplicon is amplified by PCR and analysed by bi-directional automated fluorescent DNA Sequencing.

Contact Canterbury Health Laboratories on +64 3 364 0484 or email LabInfo@cdhb.health.nz

Uncertainty of Measurement Automated bidirectional DNA sequencing has an analytical sensitivity and specificity of >99%. Note that the lower limit of variant detection of sequencing analysis is ~10%, this is important to consider in the case of mosaicism, mitochondrial, and somatic variation that is not expected to be present at 50% or 100%. This analysis will not detect variants located within intronic regions, except at the intron-exon boundaries.

Genomic DNA must be extracted from the specimen prior to testing. This incurs an additional charge (see GDNA). Laboratories may prefer to submit DNA for testing. Please provide a minimum of 5 micrograms of DNA at 20 nanograms/microlitre.

Contact Information

Enquiry Form