Related Experiment Video
Updated: Jul 3, 2026

Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry
Published on: June 21, 2018
Chromosome 17: association of a large inversion polymorphism with corticosteroid response in asthma
Kelan G Tantisira1, Ross Lazarus, Augusto A Litonjua
1Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. kelan.tantisira@channing.harvard.edu
Abstract:
A 900-kb inversion exists within a large region of conserved linkage disequilibrium (LD) on chromosome 17. CRHR1 is located within the inversion region and associated with inhaled corticosteroid response in asthma. We hypothesized that CRHR1 variants are in LD with the inversion, supporting a potential role for natural selection in the genetic response to corticosteroids. We genotyped six single nucleotide polymorphisms (SNPs) spanning chromosome 17: 40,410,565-42,372,240, including four SNPs defining inversion status. Similar allele frequencies and strong LD were noted between the inversion and a CRHR1 SNP previously associated with lung function response to inhaled corticosteroids. Each inversion-defining SNP was strongly associated with inhaled corticosteroid response in adult asthma (P values 0.002-0.005). The CRHR1 response to inhaled corticosteroids may thus be explained by natural selection resulting from inversion status or by long-range LD with another gene. Additional pharmacogenetic investigations into regions of chromosomal diversity, including copy number variation and inversions, are warranted.
Related Concept Videos
Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
Antiasthma Drugs: Inhaled Corticosteroids and Glucocorticoids
ICS work through a multifaceted mechanism of action. They suppress the inflammatory response caused by the proliferation of TH cells. They also reduce the transcription of the IL-2 gene, which is involved in the...
Asthma-IV: Diagnostic and Management
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes:
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...

