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Temple-Baraitser Syndrome and Zimmermann-Laband Syndrome via the KCNH1 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
KCNH1 81479 81479,81479 $990
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
8081KCNH181479 81479,81479 $990 Order Options and Pricing

Pricing Comments

Testing run on PG-select capture probes includes CNV analysis for the gene(s) on the panel but does not permit the optional add on of exome-wide CNV analysis. Any of the NGS platforms allow reflex to other clinically relevant genes, up to whole exome or whole genome sequencing depending upon the base platform selected for the initial test.

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

This test is also offered via a custom panel (click here) on our exome or genome backbone which permits the optional add on of exome-wide CNV or genome-wide SV analysis.

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


  • Li Fan, MD, PhD, FCCMG, FACMG

Clinical Features and Genetics

Clinical Features

Temple-Baraitser syndrome is a rare multisystem developmental disorder characterized by severe intellectual disability, epilepsy, dysmorphic facial features, and hypoplasia or aplasia of the nails of the thumbs and great toes (Jacquinet et al. 2010; Shen et al 2015; Simons et al. 2015).

Zimmermann-Laband syndrome is another rare developmental disorder characterized by facial dysmorphism including coarse face and gingival hypertrophy, hypoplasia or aplasia of nails and terminal phalanges, and hypertrichosis. Intellectual disability has been seen in patients (Kortum et al. 2015).

Temple-Baraitser syndrome and Zimmermann-Laband syndrome share not only the major feature of hypoplasia or aplasia of the nails of the thumbs and great toes, but also other minor characteristics.


Both Temple-Baraitser syndrome and Zimmermann-Laband syndrome are inherited in an autosomal dominant manner. Temple-Baraitser syndrome is caused by pathogenic variants in the KCNH1 gene (Simons et al 2015), while Zimmermann-Laband syndrome is caused by pathogenic variants in the KCNH1 or ATP6V1B2 genes (Kortum et al. 2015). The reported KCNH1 pathogenic variants either in Temple-Baraitser syndrome or Zimmermann-Laband syndrome are missense variants. To date, large deletions or large duplications in KCNH1 have not been discovered (Human Gene Mutation Database).

KCNH1 encodes potassium channel, voltage gated EAG 1 related subfamily H, member 1 (Kv10.1). The gene is predominantly expressed in the adult central nervous system and is thought to be involved in neuronal activity, cell proliferation, and development. De novo pathogenic variants in KCNH1 occur in most cases (Simons et al. 2015). An in vitro study showed Temple-Baraitser syndrome associated pathogenic variants in KCNH1 leads to deleterious gain-of-function in potassium channel activity (Simons et al 2015). Another study also suggests a gain-of-function effect for all Zimmermann-Laband syndrome-associated KCNH1 pathogenic variants (Kortum et al. 2015). When a pathogenic variant in the KCNH1 channel was co-expressed with wild-type KCNH1, it formed heterotetrameric channels which reduced conductance at positive potentials, but also pronounced conductance at negative potentials.

Clinical Sensitivity - Sequencing with CNV PG-Select

KCNH1 is the only gene known to be involved with Temple-Baraitser syndrome. Compared to Temple-Baraitser syndrome, a molecular cause in KCNH1 was identified in 25% of cases with Zimmermann-Laband syndrome (Kortüm et al. 2015).

Testing Strategy

This test provides full coverage of all coding exons of the KCNH1 gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.

Indications for Test

KCNH1 sequencing test is recommended for patients who are suspected to have Temple-Baraitser syndrome or Zimmermann-Laband syndrome.


Official Gene Symbol OMIM ID
KCNH1 603305
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT


Name Inheritance OMIM ID
Temple-Baraitser Syndrome AD 611816
Zimmermann-Laband Syndrome 1 AD 135500


  • Human Gene Mutation Database (Bio-base).
  • Jacquinet A. et al. 2010. American Journal of Medical Genetics. Part A. 152A: 2322-6. PubMed ID: 20683999
  • Kortüm F. et al. 2015. Nature Genetics. 47: 661-7. PubMed ID: 25915598
  • Shen J.J. 2015. Clinical Dysmorphology. 24: 55-60. PubMed ID: 25629734
  • Simons C. et al. 2015. Nature Genetics. 47: 73-7. PubMed ID: 25420144


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

If ordering a Duo or Trio test, the proband and all comparator samples are required to initiate testing. If we do not receive all required samples for the test ordered within 21 days, we will convert the order to the most effective testing strategy with the samples available. Prior authorization and/or billing in place may be impacted by a change in test code.

Specimen Types

Specimen Requirements and Shipping Details

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View Ordering Instructions

1) Select Test Method (Platform)

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2) Select Additional Test Options

No Additional Test Options are available for this test.

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