Heterotaxy Syndromes


Test Details
TEST CODE NGS399
TEST METHODOLOGY NGS
TAT (TURNAROUND TIME) 2 - 4 weeks
GENES 7
CPT CODE 81479
PRICE $1795
RECOMMENDED MNG KITS
  • SINGLE Blood Genetic Testing
  • Buccal Swab Genetic Testing

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Clinical Information
Clinical Significance

Heterotaxy syndrome (heterotaxia) is a clinically and genetically heterogeneous disorder in which the internal organs are abnormally arranged in the chest and abdomen across the left-right axis of the body. Individuals with this condition have complex birth defects affecting the heart, lungs, liver, spleen, intestines, and other organs. In the normal body, most of the organs in the chest and abdomen have a particular location on the right or left side; ‘situs solitus.’ Rarely, the orientation of the internal organs is completely flipped from right to left, a situation known as ‘situs inversus.’ This mirror-image orientation usually does not cause any health problems, unless it occurs as part of a syndrome affecting other parts of the body as well. Heterotaxy syndrome is an arrangement of internal organs somewhere between situs solitus and situs inversus; this condition is also known as ‘situs ambiguous’.

Signs and symptoms of heterotaxia are usually related to problems with the circulation due to the heart defects and can include cyanosis, breathing difficulties, increased risk of infections, and problems with digesting food. Severity of these conditions ranges from asymptomatic to life-threatening. Heterotaxia alters the structure of the heart, including the attachment of the large blood vessels. The most serious complications are generally caused by cardiac defects including atrioventricular septal defect (AVSD), common atrial septal defects (ASD), malposition or transposition of the great arteries (TGA), Tetralogy of Fallot (TOF), dextrocardia, and patent ductus arteriosis (PDA).

Relevant Diseases
  • Heterotaxy

Specimen Information
Acceptable Sample Types
  • Muscle
  • Cultured Fibroblasts
  • Whole Blood - EDTA
  • Extracted DNA - Leukocytes
  • Buccal Cells
Sample Preparation: (1) Blood specimens: Draw blood in an EDTA tube. Preferred volume: 4 milliliters (adults and pediatrics), Minimum volume: 2 milliliters; (2) DNA extracted from leukocytes, muscle, or fibroblasts: Preferred quantity: 4 micrograms, Minimum quantity: 3 micrograms (Genomic DNA should be eluted in sterile Dnase/Rnase free water or TE. The A260:A280 ratio should be 1.8-2.0.); (3) 2 T-25 flasks of fibroblasts; (4) 50-75 milligrams muscle snap frozen in liquid nitrogen and maintained at -80°Celsius or below. (5) Skin biopsy (Fibroblasts will be cultured from skin specimen for genetic testing): Skin biopsy may be taken from the inner forearm with a sterile skin punch (2-5 millimeters) or at incision site of muscle biopsy. Site is sterilized with alcohol swabs only (other reagents will inhibit cell isolation/growth). Biopsy site may be anaesthetized with 2% lidocaine with epinephrine. Depth of punch is 2mm. Transfer skin biopsy into 15 milliliter conical tube filled with sterile culture media. (6) Buccal cells.
Shipping Condition: MNG SmartKits are available for free shipping of specimens. Please see our website for details. If you are not using a MNG SmartKit: (1) Blood specimens should be shipped in a secure container at room temperature. (2) Extracted DNA should be shipped priority overnight at ambient temperature. (3) T-25 flasks containing fibroblasts should be shipped in an insulated container at room temperature. Flasks should be completely filled with media and cells should be ~90% confluent. Fibroblast samples must be certified free from Mycoplasma. MNG is able to perform this service for a small charge (See TC05). (4) Muscle samples should be shipped frozen in an insulated container with 5-7 lbs dry ice. (5) Buccal cells should be shipped in a secure container at room temperature. (6) Skin Biopsy: Conical containing the skin specimen should be shipped in a secure container with cold pack (DO NOT FREEZE). All samples should be shipped overnight at the proper temperature for receipt by our lab Monday thru Saturday (No Sunday or holiday deliveries accepted).

Genes Assessed
ACVR2B
CCDC11
CFC1
CRELD1
NKX2-5
NODAL
ZIC3

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