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This is a sendout test. Please note that turnaround time is defined as the anticipated time from set up day to results release.
S50070: SMA Diagnostic Test Print View
Technical Results      
SMN1      
SMN2      
Interpretation      

PRIMARY
1 Whole Blood EDTA 4 (2) mL   Refrigerated - 14 Day(s)/Room Temperature - 8 Day(s)  
ALTERNATE
  Amniotic Fl Cultured T25   Room Temperature - 48 Hour(s)  
  Whole Blood ACD Sol A 4 (2) mL   Refrigerated - 14 Day(s)/Room Temperature - 8 Day(s)  
  Whole Blood ACD Sol B 4 (2) mL   Room Temperature - 8 Day(s)/Refrigerated - 14 Day(s)  
  Whole Blood (Citrated) 4 (2) mL   Refrigerated - 14 Day(s)/Room Temperature - 8 Day(s)  
  WB EDTA Trace Metal   Refrigerated - 14 Day(s)/Room Temperature - 8 Day(s)  
  Whole Blood EDTA Pink 4 (2) mL   Refrigerated - 14 Day(s)/Room Temperature - 8 Day(s)  
  CVS Cultured cells T25   Room Temperature - 48 Hour(s)  
  CVS Biop 10-20mg in cult   Room Temperature - 48 Hour(s)  
  Saliva   Refrigerated - 14 Day(s)/Room Temperature - 14 Day(s)  
  Amniotic Fluid   Room Temperature - 48 Hour(s)  
  Whole Blood Heparin 4 (2) mL   Room Temperature - 8 Day(s)/Refrigerated - 14 Day(s)  

Spinal muscular atrophy (SMA) is one of the most common autosomal recessive diseases. SMA is characterized by the degeneration of the anterior horn cells of the spinal cord which leads to symmetric proximal muscle weakness. The estimated incidence of SMA is 1/6,000 to 1/10,000 live births with a carrier frequency of 1/40 to 1/60. Clinical presentation, mainly based upon age of onset of symptoms, is classified into 4 SMA subtypes: subtype I, onset before 6 months of age; subtype II, onset between 6 and 12 months of age; subtype III, onset in childhood after 12 months of age; and subtype IV, adult onset. Each subtype displays significant variance of clinical prognosis, including lifespan. The survival motor neuron (SMN1)gene has been shown to be responsible for 99% of SMA cases. An adjacent homologous gene, SMN2, encodes a protein identical to that of SMN1. SMA is caused by a critical reduction in the total amount of functional SMN protein. Typically 80% to 90% of SMN protein is derived from functional SMN1 genes, while 10% to 20% is derived from SMN2 genes. Therefore, SMN protein expression, or dosage, is based largely upon SMN1 gene copy number and, to a much lesser extent, SMN2 gene copy number. Loss of functional production of SMN protein most commonly occurs by deletion of SMN1 and/or SMN2 genes, either by homologous recombination or gene conversion (95% of SMA alleles). The remaining 5% of SMA alleles harbor point mutations in the SMN1 gene(s) that effectively eliminates the production of functional SMN protein from those gene copies. Although a diagnosis of SMA depends upon SMN1 gene copy number, a less severe SMA phenotype may be associated with an increased number (greater than or equal to 3 copies) of functional SMN2 gene copies. Conversely, a severe SMA phenotype may be associated with fewer (less than or equal to 2) functional SMN2 gene copies.

Do not freeze whole blood specimens. Transport at room temperature.

For prenatal diagnosis with a fetal specimen:
1) parents must be documented carriers of one of the mutations tested;

2) maternal blood or DNA must be available to rule out maternal cell
contamination (order test code 10262X);
3) contact the laboratory genetic counselor before submission.

For saliva:
Patient should rinse mouth with water and wait at least one
minute before collecting sample.

Amniotic fluid:
Normal collection procedure. Specimen stability is crucial.
Store and ship ambient immediately. Do not refrigerate or freeze.

Amniocyte or chorionic villus culture:
Sterile T25 flask, filled with culture medium. Specimen stability
is crucial. Store and ship ambient immediately. Do not refrigerate
or freeze.

Dissected chorionic villus (CVS) biopsy:
10-20 mg dissected chorionic villi collected in sterile tube,
filled with sterile culture medium. Specimen stability is crucial.
Store and ship ambient immediately. Do not refrigerate or freeze.
Do not hold cells; forward to laboratory when cells arrive.
Setup Schedule
Sunday-Saturday

Reported (Analytical Time)
7 days

CPT Code
81401

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Notes
Reject Criteria: Clotted specimen; Received frozen. Send specimen to testing lab for viability determination. Do not reject. Other acceptable specimen: 1 mL saliva submitted in Oragene DNA self collection kit OG-510 Frozen: Call Lab Method: Allele Specific Real-Time Polymerase Chain Reaction, ddCt Method Prenatal samples require added time for confirmatory testing






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