Neuronal Ceroid Lipofuscinosis Type 1 (CLN1) : PPT1 Sequencing

Test Information

PPT1 sequencing is a molecular test used to identify variants in the gene associated with Neuronal Ceroid Lipofuscinosis Type 1 (CLN1).

Turnaround Time

3 weeks

CPT Code(s)

81479

Cost

$800

Genes

  • PPT1

Clinical Information

The neuronal ceroid lipofuscinoses (CLN) are a group of conditions that are inherited in an autosomal recessive pattern. CLN1 is characterized by progressive microcephaly, contractures, developmental delay, psychiatric symptoms, and neurological degeneration including seizures and ataxia. Retinal and macular degeneration leads to blindness by the age of 2 years with diminished or abolished ERG results. Age of onset varies with infantile, late-infantile, juvenile and adult-onset forms of the disease with younger ages of onset typically associated with a more rapid progression of symptoms. The intracellular accumulation of lipopigments results in a characteristic microscopic pattern called granular osmiophilic deposits (GROD).

Indications

Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.

Methodology

Sanger Sequencing

Specimen Requirements

The preferred sample type is peripheral blood collected in an EDTA (purple top) tube - at least 2-3ml for pediatric patients and 5-6ml for adult patients. Extracted DNA, dried blood spots, and saliva are also accepted for this test. Saliva samples must be submitted in an approved saliva kit. Contact the lab to receive a saliva kit or to have one sent to your patient.

Transport Instructions

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Prenatal Testing Information

Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.

Have Questions? Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Lucy's Story

When our daughter Lucy had a metabolic crisis at 7 days old, we were shocked and devastated to find out that she was born with a rare genetic disorder (MSUD). Her newborn screening results did not make it back in time to prevent the crisis, and no one at our local hospital was familiar with the disease. They did not know how to treat her. Calls were made to Greenwood Genetic Center to confirm her diagnosis and guide her care. Dr. Champaigne and Ami...

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