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Spastic Paraplegia 5A via the CYP7B1 Gene

Summary and Pricing

Test Method

Sequencing and CNV Detection via NextGen Sequencing using PG-Select Capture Probes
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
15239 CYP7B1 81479 81479,81479 $640 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
15239CYP7B181479 81479,81479 $640 Order Options and Pricing

Pricing Comments

This test is also offered via our exome backbone with CNV detection (click here). The exome-based test may be higher priced, but permits reflex to the entire exome or to any other set of clinically relevant genes.

An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.

Turnaround Time

3 weeks on average for standard orders or 2 weeks on average for STAT orders.

Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.

Targeted Testing

For ordering sequencing of targeted known variants, go to our Targeted Variants page.


Genetic Counselors


  • Greg Fischer, PhD

Clinical Features and Genetics

Clinical Features

Spastic paraplegia 5A (SPG5A) is a type of hereditary spastic paraplegia (HSP) with a wide phenotypic spectrum (Lo Giudice et al. 2014). Some SPG5A patients have “pure” spastic paraplegia, i.e., the symptoms are primarily limited to lower limb weakness and spasticity. While in other patients, the clinical feature is complicated by distal muscle atrophy, axonal neuropathy, cerebellar ataxia, and white matter abnormalities on brain MRI (Biancheri et al. 2009; Criscuolo et al. 2009; Arnoldi et al. 2012). The age at onset of SPG5A ranges from 4-47 years (Wilkinson et al. 2003; Goizet et al. 2009).


SPG5A is inherited in an autosomal recessive (AR) manner. This disorder makes up approximately 5%-10% of AR HSP (Arnoldi et al. 2012; Denora et al. 2013; Lo Giudice et al. 2014). SPG5A is caused by pathogenic variants in the CYP7B1 gene. Pathogenic variants in this gene include missense, nonsense, splicing and frame shift variants (Human Gene Mutation Database).

CYP7B1 encodes cytochrome P450 oxysterol 7-alpha-hydroxylase (CYP7B1), an enzyme that regulates the cholesterol catabolic pathway to convert cholesterol to bile acids (Tsaousidou et al. 2008). The abnormal cholesterol metabolism in the brain is believed to be involved in the pathogenicity of SPG5A (Mignarri et al. 2014).

SPG3A is allelic with another autosomal recessive disorder, congenital bile acid synthesis defect 3. To date, two homozygous pathogenic variants have been identified to cause severe cholestasis (Setchell et al. 1998; Ueki et al. 2008).

Clinical Sensitivity - Sequencing with CNV PG-Select

It is difficult to estimate the clinical sensitivity of this test due to the lack of large cohort studies. All the reported pathogenic variants in CYP7B1 can be detected by sequencing.

Testing Strategy

This test is performed using Next-Gen sequencing with additional Sanger sequencing as necessary.

This test provides full coverage of all coding exons of the CYP7B1 gene plus 10 bases of flanking noncoding DNA in all available transcripts along with other non-coding regions in which pathogenic variants have been identified at PreventionGenetics or reported elsewhere. We define full coverage as >20X NGS reads or Sanger sequencing.

Indications for Test

Individuals with symptoms consistent with AR HSP and family members of patients who have known CYP7B1 pathogenic variants are candidates for this test. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in CYP7B1.


Official Gene Symbol OMIM ID
CYP7B1 603711
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT


  • Arnoldi A. et al. 2012. Clinical Genetics. 81: 150-7. PubMed ID: 21214876
  • Biancheri R. et al. 2009. Neuromuscular Disorders : Nmd. 19: 62-5. PubMed ID: 19187859
  • Criscuolo C. et al. 2009. Journal of Neurology. 256: 1252-7. PubMed ID: 19363635
  • Denora P.S. et al. 2013. Handbook of Clinical Neurology. 113: 1899-912. PubMed ID: 23622413
  • Goizet C. et al. 2009. Brain : a Journal of Neurology. 132: 1589-600. PubMed ID: 19439420
  • Human Gene Mutation Database (Bio-base).
  • Lo Giudice T. et al. 2014. Experimental Neurology. 261: 518-39. PubMed ID: 24954637
  • Mignarri A. et al. 2014. Journal of Neurology. 261: 617-9. PubMed ID: 24509641
  • Setchell K.D. et al. 1998. The Journal of Clinical Investigation. 102: 1690-703. PubMed ID: 9802883
  • Tsaousidou M.K. et al. 2008. American Journal of Human Genetics. 82: 510-5. PubMed ID: 18252231
  • Ueki I. et al. 2008. Journal of Pediatric Gastroenterology and Nutrition. 46: 465-9. PubMed ID: 18367963
  • Wilkinson P.A. et al. 2003. Neurology. 61: 235-8. PubMed ID: 12874406


Ordering Options

We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.

myPrevent - Online Ordering

  • The test can be added to your online orders in the Summary and Pricing section.
  • Once the test has been added log in to myPrevent to fill out an online requisition form.
  • PGnome sequencing panels can be ordered via the myPrevent portal only at this time.

Requisition Form

  • A completed requisition form must accompany all specimens.
  • Billing information along with specimen and shipping instructions are within the requisition form.
  • All testing must be ordered by a qualified healthcare provider.

For Requisition Forms, visit our Forms page

Specimen Types

Specimen Requirements and Shipping Details

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View Ordering Instructions

1) Select Test Method (Backbone)

1) Select Test Type

2) Select Additional Test Options

STAT and Prenatal Test Options are not available with Patient Plus.

No Additional Test Options are available for this test.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
Total Price: $
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