Test Code | D4044 |
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Test Summary |
This test analyzes the ABCD1 gene, which is associated with X-linked adrenoleukodystrophy. |
Turn Around Time | 3 - 5 weeks |
Acceptable Sample Types | DNA, Isolated , Dried Blood Spots , Saliva , Whole Blood (EDTA) |
Acceptable Billing Types | Institutional Billing , Self (patient) Payment |
NY Approved | No |
CPT Codes** | 81479(x2) |
This gene sequencing panel includes both sequencing and deletion/duplication (CNV) analysis for all coding regions of the ABCD1 gene. Analysis is performed utilizing both LR-PCR followed by NGS sequencing and MLPA. All variants are classified according to American College of Genetics and Genomics (ACMG) guidelines.
X-linked adrenoleukodystrophy is a disease that primarily affects the nervous system and adrenal glands. There are three forms of X-linked adrenoleukodystrophy, and the disease occurs mainly in males. The cerebral form of X-linked adrenoleukodystrophy typically has an age of onset in childhood with symptoms of learning difficulty, behavioral problems, vision problems, difficulty swallowing, poor coordination, and impaired adrenal function. Death usually occurs a few years after symptoms begin. The adrenomyeloneuropathy form of X-link adrenoleukodystrophy typically occurs in adulthood with symptoms of progressive stiffness and weakness in the legs, urinary and genital tract disorders, behavioral changes, and adrenocortical insufficiency. In severely affected individuals, the disease can lead to an early death. The Addison disease form of X-linked adrenoleukodystrophy has a variable age of onset, with the symptom of adrenocortical insufficiency being the hallmark feature. The disease gradually progresses, and by middle age, the symptoms of the adrenomyeloneuropathy form are present. In severely affected individuals, the condition can lead to an early death. It is estimated that the incidence of X-linked adrenoleukodystrophy is ~ 1 in 20,000
ABCD1 gene specific long-range PCR was performed to capture the genomic sequences for the real ABCD1 gene from this individual’s genomic DNA to prevent pseudogene from being co-amplified. Next-generation sequencing (NGS) was performed on an Illumina system with 100 base pair paired-end reads. Variants for the ABCD1 gene are evaluated using the Adrenoleukodystrophy Database (www.x-ald.nl) in addition to other mutation databases such as the Human Gene Mutation Database (HGMD) and published literature. This analysis cannot detect variants in regions not analyzed such as promoters, deep intronic regions. Copy number variation (CNV) analysis was assessed using MLPA or by manual reviewing of NGS reads using IGV viewer. This analysis cannot determine the location or orientation of a duplication. This assay is not designed to detect mosaicism; possible cases of mosaicism may be investigated at the discretion of the laboratory director.
Collection | Required DNA Quantity by Test Type*:
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Sample Condition | * Required DNA Quality: High molecular weight DNA (>12kb). A260/A280 reading should be ≥ 1.8. A260/230 a ratio range of 1.8 to 2.2. Contact the laboratory for specific amounts if total ng cannot be met. |
Shipping | Ship overnight at ambient temperature. |
Special Sample Instructions |
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Collection Container(s) | EDTA (purple top) |
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Collection | Infants (< 2-years): 2 to 3 mL; Children (>2-years): 3 to 5 mL; Older children and adults: Minimum 5mL. The blood tube should be inverted several times immediately after blood collection to prevent coagulation. |
Sample Condition | Store at ambient temperature. Do not refrigerate or freeze. |
Shipping | Ship overnight at ambient temperature ensuring receipt within 5-days of collection. |
Special Sample Instructions | Clotted or hemolyzed samples are not accepted. |
Collection Container(s) | Oragene™ Saliva Collection Kit or ORAcollect-Dx kit |
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Collection | Collect saliva on an Oragene™ Saliva Collection Kit ORAcollect-Dx kit according to the manufacturer's instructions. |
Sample Condition | Store at ambient temperature. Do not refrigerate or freeze. |
Shipping | Ship overnight at ambient temperature. |
Special Sample Instructions | Please contact Revvity Omics to request the saliva collection kit for patients who cannot provide a blood sample as whole blood is the preferred sample. Testing using Saliva swabs is currently not available for customers in India. Contact the Revvity Omics laboratory for more information. |
Collection Container(s) | Dried blood spot card |
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Collection | Follow kit instructions. Briefly, allow blood to saturate the card until indicated areas are filled and blood has soaked through the card. Air dry the card at ambient temperature for at least 3 hours.
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Sample Condition | Follow the instructions provided with the collection set. Store the dried blood at ambient temperature for up to two days. If the specimen cannot be sent as soon as it is dry, the filter paper should be placed in a sealable plastic bag and stored in a refrigerator (≤ 8°C) or preferably in a freezer. |
Shipping | Follow kit instructions. Double bag and ship overnight at ambient temperature. |