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Test Code SK FANC UM Fibroblast Fanconi Anemia Breakage

Important Note

Skin biopsies for this test are typically cultured inhouse in the cytogenetics lab prior to sending out. Contact for questions.

Clinical System Name

Fibroblast Fanconi Anemia Breakage


Fanconi, Skin

Sample Requirements

Specimen: Skin

Container(s): Fibroblast Transport Media

Preferred Vol: 3 mm full thickness skin biopsy obtained under sterile conditions or Two T-25 flasks of cultured fibroblasts

Minimum Vol: None specified





Processing Instructions

Reject due to:

Spin: N


Temp: RT

Storage location: Keep sample at room temperature. Store specimen and labels in the Send Outs room temperature box in CPA.


If sending skin biopsy the specimen must arrive at OHSU lab no more than 24 hours after collection. Notify Send Outs immediately.


Off-site collection:  Keep sample at room temperature


Specimen Type Temperature Time
Skin Room temp  
  Refrigerated N
  Frozen N
T-25 flasks    



STAT Performed TAT
N  Drawn Daily; performed M - Sa ~28 d (Growth dependent)


Performing Laboratory

OHSU Genetics Lab



OHSU Genetics Lab

2525 SW 3rd Ave; Ste 350
Portland, OR 97201

Phone Number:  (503) 494-5400, (855) 535-1329



Reference Range

Interpretive report provided.


Method: Cells are cultured in the presence of the clastogens mitomycin C (MMC) and diepoxybutane (DEB).  Metaphase chromosomes are prepared from each culture and stained with Wright stain.  Fifty metaphases are scored from each culture for the presence of breaks and radial formations.

Analytical Volume: None specified


Special Instructions

Links to:


OHSU Knight Diagnostics

Clinical Utility

Chromosome breakage analysis is a test for assessing genomic instability.  The most common syndrome for which this test is diagnostic is Fanconi Anemia (FA).  FA is characterized by bone marrow failure, increased risk for cancer, and physical abnormalities.  Progressive bone marrow failure is responsible for the most significant morbidity and mortality.  Clinically heterogeneous, FA individuals are at increased risk for acute myelogenous leukemia, myelodysplastic syndrome, and solid tumors of the neck, head, oral cavities, and genitourinary system.  Congenital abnormalities are present in approximately 70% of FA patients and include: café au lait spots or hypopigmentation; short stature; radial ray defects; eye defects such as microphthalmia; malformations of the kidney, genitalia, heart, gastrointestinal tract, ears, and feet.  Currently, 16 genes have been identified that, when mutated, can cause FA.  


The first step in FA diagnosis is to perform a breakage analysis on peripheral blood.  However, some FA patients undergo a self-correction of cells in the hematopoietic lineage, resulting in a normal blood breakage study.  In such a case, breakage analysis of skin fibroblasts is necessary to detect the increased breakage and radial formation.   This phenomenon is known as somatic mosaicism.  Fibroblast breakage studies may also be preferable for patients with very low white blood cell counts.

Send Out Instructions


Reference Test Name: Breakage Analysis: Skin Chromosome Study
Reference Test Number: 6080

Ship the specimen overnight express, using the FedEx priority overnight label provided. The specimen must arrive at the lab no more than 24 hours after collection.