Overview

Disorders of mitochondrial energy generation can be caused by mutations in approximately 200 different nuclear genes as well as in mitochondrial DNA. Mutations in some nuclear genes cause distinct genotype/phenotype correlations that may prompt candidate gene analysis. Autosomal recessive SURF1 mutations are a common cause of Leigh syndrome, particularly when there is relative cognitive sparing. Autosomal recessive POLG mutations can cause a range of disorders such as Alpers-Huttenlocher syndrome, ataxia-neuropathy spectrum and related disorders, while autosomal dominant POLG mutations can cause chronic progressive external ophthalmoplegia with multiple mtDNA deletions. For other presentations suggestive of a nuclear-encoded mitochondrial disorder we recommend performing clinical exome sequencing.

Category

Cost

Next Generation Sequencing (NGS) gene panel (PolG and SURF1): $1,000

Carrier testing by Sanger sequencing (PolG or SURF1): $250

Prenatal testing by Sanger sequencing (PolG or SURF1): $600

Reporting time

NGS panel (POLG; SURF1): 12 weeks

Carrier testing (PolG or SURF1): 4- 6 weeks

Prenatal testing (PolG and SURF1): 1- 3 weeks

Contacts

Dr Belinda Chong

Phone (03) 9936 6550

Specimen Requirements

EDTA blood: Adult: 2 x 5 ml

Prenatal:

Amniotic Fluid 20ml

Chorionic Villus 20mg

Notes

Blood Storage Requirements: Do not freeze. Store at 4°C or room temperature.

Genes tested