MDP1; MIRAS; MTDPS4A; MTDPS4B; PEO; POLG1; POLGA; SANDO; SCAE
The POLG gene is associated with a spectrum of related autosomal recessive conditions (MedGen UID: 60012) including mitochondrial DNA depletion syndrome 4A (Alpers type; MTDPS4A), mitochondrial DNA depletion syndrome 4B (MNGIE type; MTDPS4B), sensory ataxic neuropathy, dysarthria, and ophthalmoparesis (SANDO), spinocerebellar ataxia with epilepsy (SCAE), and progressive external ophthalmoplegia with mitochondrial DNA deletions 1 (PEOB1). In addition, the POLG gene is associated with autosomal dominant progressive external ophthalmoplegia with mitochondrial DNA deletions 1 (PEOA1)(MedGen UID: 371919).
Pathogenic variants in the POLG gene are associated with ~87% of clinical cases of Alpers-Huttenlocher syndrome.
Mitochondria are specialized organelles that produce much of the cell’s energy. Despite being an intrinsic part of the cell, mitochondria still maintain a small genome, independent of the nuclear DNA. The POLG gene encodes for the mitochondrial DNA polymerase that is important for the proper development and maintenance of mitochondria (PMID: 23545419).
Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).
Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence, and select noncoding variants. Our assay provides a Q30 quality-adjusted mean coverage depth of 350x (50x minimum, or supplemented with additional analysis). Variants classified as pathogenic or likely pathogenic are confirmed with orthogonal methods, except individual variants that have high quality scores and previously validated in at least ten unrelated samples.
Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.
|Gene||Transcript reference||Sequencing analysis||Deletion/Duplication analysis|