Associated disorders

The TPP1 gene is associated with autosomal recessive neuronal ceroid lipofuscinosis (NCL) type 2 (MedGen UID: 406281).

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Pathogenic variants in the TPP1 gene are associated with ~97% of neuronal ceroid lipofuscinosis (NCL) type 2 (CLN2).

The cell is continually producing essential building blocks for life, such as proteins, metabolites, sugars, and lipids. These components are also continually degraded as they become damaged, overabundant, or unnecessary. If this balance is disrupted, then excess components can accumulate in the cell, interfering with normal function and causing toxicity. Defects in lysosomes, acidic cellular organelles that degrade cellular components, cause a group of conditions known as lysosomal storage disorders. The TPP1 gene, also called CLN2 in the literature, encodes a protein involved in endocytosis and cell death.

Assay and technical information

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
TPP1 NM_000391.3