Case study

A New Era is Emerging for Ion Channel
and Channelopathy ResearchTools:
SyncroPatch 384

Alfred L. George, Jr., MD
featured by Nanion Technologies
Alfred L. George, Jr., MD is the Magerstadt

is often the case when insufficient data exist to distinguish

Professor and Chair of the Department ofbenign from pathogenic changes. This distinction is critically

Pharmacology and Director of the Center forimportant in clinical medicine for making a proper diagnosis,

Pharmacogenomics at Northwestern University

planning appropriate genetic and reproductive counseling,

Feinberg School of Medicine. His work hasand in some cases for devising a clinical management plan.

contributed greatly to understanding themechanisms by which ion channel mutations

A widely used approach for classifying genetic variants

cause a variety of inherited disorders ofenables inclusion of functional evidence demonstrating

membrane excitability.

a damaging effect of a variant into the interpretation.
Unfortunately for most genes, functional evidence tosupport or refute pathogenicity is challenging to obtain.

The channelopathy field is an exciting branch of ionchannel research that combines human genetics, cellularelectrophysiology, and pharmacology. The main goals of thisfield are to elucidate the molecular mechanisms of diseases
caused by ion channel dysfunction, and to develop more
personalized treatment strategies basedon an individual’s DNA sequence.
Ion channels are encoded by specific genes that exhibit
nucleotide and amino acid sequence variation amongindividuals in the general population. In rare cases, specificmutations cause altered function or impaired trafficking of
an ion channel protein. Channelopathy is the term used
to describe those disorders associated with mutations in ion
channel genes. In recent years, there has been accelerated
effort to sequence genes and genomes in persons with allforms of genetic diseases as well as healthy people and thishas led to an explosion in the number of genetic variants
discovered. However, the interpretation of findings fromgenetic studies can be difficult when variants are classified by
the designation ‘variant of unknown significance’ (VUS), which

Nanion's SyncroPatch 384 platform(successor of SyncroPatch 384PE and SyncroPatch384i) allows effortless high-throughput ion channel
screening coupled with high flexibility and reliability,
due to the combination of its patch clamp modulewith Beckman Coulter’s new i-Series liquid handlingrobot Biomek i5.

Fortunately, this is not the case for genes encoding ion
channels, which can be assayed with well-establishedexperimental paradigms and methodologies. The gold
standard approach for assessing functional effects of ionchannel variants is patch clamp electro-physiology. But,
this approach is tedious, time- and labor-intensive, andnot scalable to match the rampant discovery of new ionchannel variants.

“The SyncroPatch has revolutionized our ability to determine thefunctional consequences of hundreds of human ion channelvariants, which could be considered one of the most significant
recent advances in channelopathy research.”
Alfred L. George, Jr., MD, Northwestern University Feinberg School of Medicine

In the past few years, an emerging group of pioneering

were associated with congenital long-QT syndrome or genetic

researchers have utilized high throughput automatedepilepsy, respectively. One year later, they upgraded thepatch clamp instrumentation, originally designed for drug

instrument to have a second 384-well module (SyncroPatch

discovery, to study ion channel variants at an unprecedented768PE) because of the tremendous initial success withscale. The SyncroPatch 384PE system, has emerged as thethis system. To date his lab has characterized the electro-automated patch clamp system of choice among these

physiological properties of more than 200 variants in voltage-groups. A pioneer in the study of ion channel variants has

gated sodium and potassium channels using the SyncroPatch

been Dr. Al George, Magerstadt Professor, Chair of the768PE system,1-4 with many more in the pipeline. Determining

Department of Pharmacology, and the Director of the Center

the functional effects of ion channel variants can help withfor Pharmacogenomics, Northwestern University Feinberg

classification as potentially disease causing or not. In their

School of Medicine. He recognized the great potential of highrecent study of long QT syndrome type 1, the George (cont.)

throughput automated electrophysiology to determine thelaboratory was able to reclassify >65% of KCNQ1 (encoding

functional consequences of ion channel variants. His lab had

KV 7.1) variants of uncertain significance as likely pathogenic.1

the foresight to purchase a SyncroPatch 384PE system in 2014
to characterize cardiac and brain ion channel variants that

Most recently, they presented a study of 80 KCNQ2 variants at
the annual meeting of the American Epilepsy Society.

The SyncroPatch 768PE recordings of the cardiac slow delayed rectifier current (IKs) from
CHO cells expressing KCNQ1 and KCNE1. The figure shows a snapshot of SyncroPatch 768PE
software, measurements made at Northwestern University. Green fields represent successfulrecordings, indicating a success rate of approx. 95%.

Once functional defects in ion channel variants are

SyncroPatch that can estimate single channel conductance andidentified, researchers can evaluate whether existing drugs

surface expression (Nanion User meeting 2019). They presented

or investigational compounds can correct the dysfunction,a methodology to predict gain-of-function (GOF) and loss-of-and potentially translate this information to more precise

function (LOF) and then validated the model by studying 50

pharmacotherapy in the clinic. The potential for this strategy

variants on the SyncroPatch 384 system.7

to change the treatment of human channelopathies isremarkable and enables a new way of looking at ion channel

Researchers at the Victor Chang institute in Australia publisheddiseases and their treatment.

a paper recently assessing the functional properties of 30

While this pioneering work is still emerging and its potential isvariants of the KCNH2 gene encoding the KV 11.1 (or hERG)
channel, which is a major gene responsible for congenital

being rapidly realized, other labs have also embraced thelong QT syndrome.8,9 Using the SyncroPatch 384PE systemSyncroPatch 384PE to perform similar studies. Jen Pan Ph.D.,

they examined the full range of functional attributes ofDirector, Translational Neurobiology at the Stanley Center ofheterologously expressed hERG channels and were able tothe Broad Institute, is another early adopter of the Syncro-distinguish benign from pathogenic variants.

Patch platform, working with it since early 2016.5-7
Her laboratory and collaborators are using SyncroPatch

In another recent paper, researchers at Vanderbilt University

recordings to study the mechanism of action of ion channel

studied cardiac sodium channel (SCN5A gene encoding NaV

modulators identified from high throughput FLIPR assays. In1.5) variants associated with Brugada and long QT syndromes.10

addition, her group characterized genetic variants of genes

They studied 83 SCN5A variants including 10 positive and 10

that encode voltage-gated sodium and calcium channels thatnegative controls. They identified 45 new or partial loss-of-

are implicated in schizophrenia and neurological disorders.

function variants, and were able to reclassify 50 of 60 variants

They developed novel methods for noise analyses using theof uncertain significance using the SyncroPatch 384PE system.

Dr. Carlos Vanoye explains the Northwestern University SyncroPatch 768PE to Will Hutson and Leah Schust from theFamilie SCN2A Foundation. Together with the members of the foundation, researchers at Northwestern University
are collaborating with focus on a sodium channelopathy involved in neuronal disorders (SCN2A encodes one ofthe brain sodium channels involved with epilepsy and autism). For more information, visit www.scn2a.org.

“We believe the SyncroPatch platform will transform our approachto determining the most effective pharmacological remedyfor certain channelopathies, and enable a precision medicine
approach to these rare genetic conditions.”
Alfred L. George, Jr., MD, Northwestern University Feinberg School of Medicine

Many more variants associated with ion channel diseases
are identified every year through clinical genetic testing andgenomic research studies. A large proportion of the identified

References
1.

D, Meiler J, Sanders CR, George AL, Jr. High-Throughput Functional Evaluation

variants get classified as variants of unknown significance, butof KCNQ1 Decrypts Variants of Unknown Significance. Circ Genom Precis Med.

the use of automated electrophysiology on platforms such as2018; 11:e002345.

the SyncroPatch 384PE can provide much needed functional
data to better classify these variants.

Vanoye CG, Desai RR, Fabre KL, Gallagher SL, Potet F, DeKeyser JM, Macaya

2.

Kang SK, Vanoye CG, Misra SN, Echevarria DM, Calhoun JD, O’Conner JB,
Fabre KL, McKnight D, Demmer L, Goldenberg P, Grote LE, Thiffault I, Saunders

Automated patch clamp systems such as the SyncroPatchC, Strauss KA, Torkamani A, van der Smagt JJ, van Gassen KL, Carson RP, Diaz

384PE are poised to further transform the channelopathy field

J, Leon E, Jacher JE, Hannibal MC, Litwin J, Friedman NR, Schreiber A, Lynchenabling researchers the throughput needed to determine

B, Poduri A, Marsh ED, Goldberg EM, Millichap JJ, George AL, Jr., Kearney JA.

the functional consequences of newly discovered ion channel

Spectrum of KV 2.1 dysfunction in KCNB1-associated neurodevelopmentalvariants, collect novel data on structure-function relationships,disorders. Ann Neurol. 2019; 86:899-912.

ascertain molecular mechanisms of disease, and to elucidate
variant-specific pharmacological profiles that may improve3.

Calhoun JD, Vanoye CG, Kok F, George AL, Jr., Kearney JA. Characterizationof a KCNB1 variant associated with autism, intellectual disability, and epilepsy.

clinical management.

Neurol Genet. 2017; 3:e198.
4.

Gertler TS, Thompson CH, Vanoye CG, Millichap JJ, George AL, Jr. Functional
consequences of a KCNT1 variant associated with status dystonicus and earlyonset infantile encephalopathy. Ann Clin Transl Neurol. 2019; 6:1606-1615.

Contact Information

5.

put Assays to Analyze and Screen Electrophysiological Phenotypes. Methods

Alfred L. George, Jr., MD

Mol Biol. 2018; 1787:235-252.

Chair, Department of Pharmacology; Director, Center
for Pharmacogenomics; Magerstadt Professor of

Pan JQ, Baez-Nieto D, Allen A, Wang HR, Cottrell JR. Developing High-Through6.

Heyne HO, Baez-Nieto D, Iqbal S, Palmer D, Brunklaus A, Epi25 Collaborative,Pharmacology

Johannesen KM, Lauxmann S, Lemke JR, Moller RS, Perez-Palma E, Scholl

Northwestern University

U, Syrbe S, Lerche H, May P, Lal D, Campbell AJ, Pan J, Wang HR, Daly MJ.

Feinberg School of Medicine

Predicting Functional Effects of Missense Variants in Voltage-Gated Sodium andSearle Building Room 8-510

Calcium Channels. bioRxiv. 2019; 671453.

320 E Superior
Chicago IL 60611

7.

CaV 3.3 (CACNA1I) and schizophrenia: A case study in what we can learn fromwww.pharm.northwestern.edu/

human population genetics to understand structure-function relationships inion channels. Biophysical Society Thematic Meeting: Emerging Concepts in Ion

Jen Pan, Ph.D.

Channel Biophysics. 2019; Mexico City, Mexico, October 10-13, 2017.

Director, Translational Neurobiology; Institute Scientist
Broad Institute of MIT and Harvard

Baez-Nieto D, Allen A, Goshal A, Yang L, Pan JQ. The T-type calcium channel

8.

Ng C, Perry MD, Liang W, Smith NJ, Foo B, Shrier A, Lukacs GL, Hill AP,The Ted and Vada Stanley Building,Vandenberg JI. High-throughput phenotyping of heteromeric human

75 Ames Street

ether-à-go-go-related gene potassium channel variants can discriminate

Cambridge, MA 02411

pathogenic from rare benign variants. Heart Rhythm. 2019; doi:org/10.1016/j.

www.broadinstitute.org/bios/jen-panhrthm.2019.09.020.

Acknowledgments
We thank Al and Jen for sharing their views on theimportance of ion channel and channelopathy

9.

Vanoye CG, George AL, Jr. Decoding KCNH2 variants of unknown significance.
Heart Rhythm. 2019; DOI:10.1016/jhrthm.2019.10.009.

10. Glazer AM, Wada Y, Li B, Muhammad A, Kalash OR, O’Neill MJ, Shields T,research. We are grateful for your valuable insights

Hall L, Short L, Blair MA, Kroncke BM, Capra JA, Roden DM. High-throughput

and wonderful collaboration.

reclassification of SCN5A variants. bioRxiv. 2019; 858175.

Nanion Technologies GmbH I Ganghoferstr. 70A, 80339 Munich, Germany+49 89 2190 95-0 I info@nanion.de I www.nanion.de