Heterotaxy and Situs Inversus NGS Panel

  • Panel Description
  • Test Description
  • CPT Codes
  • Resources

Panel Description

Situs Inversus
The Heterotaxy and Situs Inversus Panel examines 22 genes associated with heterotaxy and situs inversus.

Patients with a personal and/or family history consistent with heterotaxy and/or situs inversus. Heterotaxy is a condition that involves the internal organs being abnormally arranged within the body, while situs inversus is defined as one’s internal organs being completely flipped within the body and having a mirror image presentation from what you would normally expect. Symptoms for heterotaxy and/or situs inversus include, but are not limited to, blue tinted skin, difficulty breathing, rapid breathing, poor weight gain, and multiple infections.

Patients identified with heterotaxy and/or situs inversus can benefit from increased surveillance and preventative steps to better manage their risks. Medical intervention can include corrective surgery and/or medications to protect the heart and help prevent infection. Also, your patient’s family members can be tested to help define their risk. If a pathogenic variant is identified in your patient, close relatives (children, siblings, parents) could have as high as a 50% risk to also be at increased risk. In some cases, screening should begin in childhood.

Test Description

  • Sequencing
  • Del/Dup
  • Rush / STAT
  • Exclude VUS
  • MCC
  • Duo/Trio
3 - 5 weeks
Call for details
96% at 20x
Blood (two 4ml EDTA tubes, lavender top) or Extracted DNA (3ug in EB buffer) or Buccal Swab or Saliva (kits available upon request)
All sequencing technologies have limitations. This analysis is performed by Next Generation Sequencing (NGS) and is designed to examine coding regions and splicing junctions. Although next generation sequencing technologies and our bioinformatics analysis significantly reduce the contribution of pseudogene sequences or other highly-homologous sequences, these may still occasionally interfere with the technical ability of the assay to identify pathogenic variant alleles in both sequencing and deletion/duplication analyses. Sanger sequencing is used to confirm variants with low quality scores and to meet coverage standards. If ordered, deletion/duplication analysis can identify alterations of genomic regions which include one whole gene (buccal swab specimens and whole blood specimens) and are two or more contiguous exons in size (whole blood specimens only); single exon deletions or duplications may occasionally be identified, but are not routinely detected by this test. Identified putative deletions or duplications are confirmed by an orthogonal method (qPCR or MLPA). This assay will not detect certain types of genomic alterations which may cause disease such as, but not limited to, translocations or inversions, repeat expansions (eg. trinucleotides or hexanucleotides), alterations in most regulatory regions (promoter regions) or deep intronic regions (greater than 20bp from an exon). This assay is not designed or validated for the detection of somatic mosaicism or somatic mutations.

Gene Notes
ZIC3 The current testing method does not assess trinucleotide repeat expansions in this gene.
CPT Code 81479x2

NOTE:  The CPT codes listed on the website are in accordance with Current Procedural Terminology, a publication of the American Medical Association. CPT codes are provided here for the convenience of our clients. Clients who bill for services should make the final decision on which codes to use.


- Kim, S.J. Heterotaxy syndrome. Korean Circ J. 2011;41:227–232 (2011)
- Robinson, P.J. Situs inversus: When an incidental finding is not so incidental. Paediatr Child Health. 2017 Jul;53(7):715-716. doi: 10.1111/jpc.13591 (2017)