Note:
For paediatric samples a minimum of 0.5ml blood EDTA can be processed. (Microcollect)
Transport all bloods at room temperature within 24-48 hours. If necessary specimens can be refrigerated overnight for transport at room temperature the following day.
For testing of other sample types please contact the laboratory prior to sending.
Urgent TAT for prenatal analysis: 2 weeks
PCR-based amplification and subsequent fluorescence-based capillary electrophoresis is used to detect CAG repeat expansions within the Huntingtin (HTT) gene - NM_001388492.1. A Triplet-repeat Primed (TP) PCR amplification and subsequent fluorescence-based capillary electrophoresis were used to detect all sizes of expansion within the HTT gene. Due to the nature of the assay, we estimate that the CAG repeat allele sizing is correct to plus or minus one repeat for alleles ?40 repeats and up to plus or minus two for alleles >40 repeats.
Huntington disease (HD) is a progressive disorder of motor, cognitive, and psychiatric disturbances. The mean age of onset is 35 to 44 years and the median survival time is 15 to 18 years after onset. The diagnosis of HD rests on positive family history, characteristic clinical findings, and the detection of an expansion of CAG trinucleotide repeats in the HTT gene.
REFERRAL REQUIREMENTS:
Diagnostic testing requires referral through Genetic Services or Neurology. Except for Juvenile HD or pregnancy related cases which should be referred only through Genetic Services. All predictive and presymptomatic testing only through Genetic Services.
CONTACT:
Genetic Health Service NZ can be contacted on 0800 476 123.
Neurology can be contacted on (09) 307 4949 ext. 25662
To contact the Molecular Genetics team:
Auckland City Hospital
(09) 307 4949
Lablink
ext 22000
Molecular Genetics Office
ext 22014