Congenital Fibrosis of Extraocular Muscles (Ocular Motility Disorder) or Strabismus Syndromes Panel

Summary and Pricing

Test Method

Exome Sequencing with CNV Detection
Test Code Test Copy GenesCPT Code Copy CPT Codes
2685 CHN1 81479,81479 Add to Order
ECEL1 81479,81479
HOXA1 81479,81479
HOXB1 81479,81479
KIF21A 81479,81479
PHOX2A 81479,81479
ROBO3 81479,81479
SALL4 81479,81479
TUBB2B 81479,81479
TUBB3 81479,81479
Full Panel Price* $890
Test Code Test Copy Genes Total Price CPT Codes Copy CPT Codes
2685 Genes x (10) $890 81479(x20) Add to Order

Pricing Comments

We are happy to accommodate requests for testing single genes in this panel or a subset of these genes. The price will remain the list price. If desired, free reflex testing to remaining genes on panel is available. Alternatively, a single gene or subset of genes can also be ordered via our PGxome Custom Panel tool.

Targeted Testing

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

Turnaround Time

18 days on average


Genetic Counselors


Clinical Features and Genetics

Clinical Features

Strabismus syndromes or congenital fibrosis of extraocular muscles (CFEOM) is an eye movement disorder characterized mainly by non-progressive, restrictive ophthalmoplegia [inability to move the eyes with or without ptosis (droopy eyelids)] of the extraocular muscles (EOM) and congenital blepharoptosis (Heidary et al. 2008).


Congenital fibrosis of extraocular muscles (CFEOM) is a heterogeneous group of strabismus syndromes that may be associated with other anomalies. Depending on the gene, the disease has been categorized into different types (Oystreck et al. 2011; Traboulsi 2004; Whitman et al. 1993).

CFEOM1A and CFEOM3B - due to KIF21A variants (missense and small deletion) (Human Gene Mutation Database).

CFEOM1B - due to TUBB3 variants (missense)

CFEOM2 - due to PHOX2A variants (missense, nonsense and splicing)

CFEOM3A - due to TUBB3 and TUBB2B variants (missense in both)

Duane-radial ray syndrome - due to SALL4 variants (missense, nonsense, small and large deletions and duplications)

Duane retraction syndrome DURS2 - due to CHN1 variants (missense)

Isolated Duane anomaly- due to HOXA1 variants (missense, nonsense, small deletions and duplications)

Horizontal gaze palsy with progressive scoliosis (HGPPS) - due to ROBO3 variants (missense, nonsense, splicing, small deletions and duplications)

Facial weakness, hearing loss, and complex or common strabismus - due to HOXB1 variants (missense)

Distal arthrogryposis associated with unilateral ptosis ophthalmoplegia, and/or strabismus ECEL1 variants (missense, nonsense, splicing, small deletions and duplications)

CFEOM4, CFEOM5, Tukel syndrome (no genes identified yet)

CFEOM1A, CFEOM1B, CFEOM3, CFEOM3 with polymicrogyria are inherited in an autosomal dominant (AD) manner. CFEOM2 is inherited in an autosomal recessive manner. Other syndromic disorders CHN1and SALL4-associated Duane syndromes are inherited in an AD manner. Isolated DA, HGPPS, HOXB1 and ECEL1-associated disorders are inherited in an AR manner (Whitman et al. 1993)

See individual gene test descriptions for information on molecular biology of gene products.

Testing Strategy

This panel typically provides ≥98% coverage of all coding exons of the genes 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 coverage as ≥20X NGS reads or Sanger sequencing.

Since this test is performed using exome capture probes, a reflex to any of our exome based tests is available (PGxome, PGxome Custom Panels).

Clinical Sensitivity - Sequencing with CNV

Predicting clinical sensitivity for this panel is challenging due to genetic heterogeneity of Congenital fibrosis of extraocular muscles (CFEOM). Approximately 55% of the CFEOM cases are due to pathogenic variants in KIF21A , ~35% cases are due to TUBB3, ~10% cases are due to PHOX2A and <1% of the cases are due to TUBB2B (Whitman et al. 1993).

To our knowledge, only SALL4 has been reported have recurrent copy number variants. No other genes in this panel are reported to have any copy number variants to date (Human Gene Mutation Database).

Indications for Test

Patients with congenital abnormalities of eye movements are candidates (Oystreck et al. 2011;


Official Gene Symbol OMIM ID
CHN1 118423
ECEL1 605896
HOXA1 142955
HOXB1 142968
KIF21A 608283
PHOX2A 602753
ROBO3 608630
SALL4 607343
TUBB2B 612850
TUBB3 602661
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Related Test



  • Heidary G. et al. 2008. Seminars in Ophthalmology. 23: 3-8. PubMed ID: 18214786
  • Human Gene Mutation Database (Bio-base).
  • NANOS Collection of Unusual Congenital Ocular Motility Disorders and Strabismus
  • Oystreck D.T. et al. 2011. Journal of neuro-ophthalmology. 31: 69-77.  PubMed ID: 21317732
  • Traboulsi E.I. 2004. Transactions of the American Ophthalmological Society. 102: 373-89. PubMed ID: 15747768
  • Whitman M. et al. 1993. Congenital Fibrosis of the Extraocular Muscles. In: Pagon RA, Adam MP, Ardinger HH, Bird TD, Dolan CR, Fong C-T, Smith RJ, and Stephens K, editors. GeneReviews(®), Seattle (WA): University of Washington, Seattle. PubMed ID: 20301522


Ordering Options

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.

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.

Specimen Types

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