Related Experiment Video
Updated: Jul 22, 2026
11:35
The Multiple Sclerosis Performance Test (MSPT): An iPad-Based Disability Assessment Tool
Published on: June 30, 2014
Twin concordance and sibling recurrence rates in multiple sclerosis
C J Willer1, D A Dyment, N J Risch
1Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, United Kingdom.
Summary
This Canadian study found higher multiple sclerosis (MS) concordance in identical twins (monozygotic, MZ) than fraternal twins (dizygotic, DZ), especially in females. Twinning did not impact MS prevalence or risk to siblings.
Area of Science:
- Neurology
- Genetics
- Epidemiology
Background:
- Twin studies are crucial for understanding the genetic and environmental contributions to complex diseases like multiple sclerosis (MS).
- Traditional twin studies often face limitations in sample size and ascertainment, restricting comparisons to concordance rates between monozygotic (MZ) and dizygotic (DZ) twins.
- A large, population-based Canadian twin registry provides a unique opportunity to overcome these limitations.
Purpose of the Study:
- To report the final results of a longitudinal, population-based study of twins with multiple sclerosis (MS) in Canada.
- To conduct comprehensive concordance comparisons between MZ twins, DZ twins, and their non-twin siblings.
- To investigate the influence of twinning on MS prevalence and sibling risk.
Main Methods:
- A longitudinal, population-based study ascertained approximately 75% of Canadian MS twin pairs, resulting in a large sample size (n=370).
- Bias was minimized through rigorous ascertainment protocols.
- Probandwise concordance rates were calculated for monozygotic (MZ) twins, dizygotic (DZ) twins, and non-twin siblings.
Main Results:
- Probandwise concordance rates were 25.3% for MZ twins, 5.4% for DZ twins, and 2.9% for non-twin siblings.
- Significantly higher concordance was observed in MZ twins compared to DZ twins.
- The excess concordance in MZ twins was primarily driven by like-sexed female pairs (34% vs. 3.8% for female DZ pairs).
- No significant MZ/DZ difference was found in males due to small sample size.
- A non-significant 2-fold increase in risk was observed for DZ twins compared to non-twin siblings.
Conclusions:
- Multiple sclerosis (MS) has a higher concordance rate in identical (monozygotic) twins than fraternal (dizygotic) twins, indicating a significant genetic component.
- The genetic influence on MS susceptibility is particularly pronounced in females.
- Twinning itself does not appear to alter the overall prevalence of MS or the risk conferred to siblings.
Related Concept Videos
01:35Pedigree Analysis
Overview
01:49Probability Laws
Overview
01:43Sex Linked Disorders
Like autosomes, sex chromosomes contain a variety of genes necessary for normal body function. When a mutation in one of these genes results in biological deficits, the disorder is considered sex-linked.
02:26Comparing Copy Number Variations and SNPs
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
01:20Kendall's Coefficient of Concordance
Kendall's Coefficient of Concordance (W), also known as Kendall's W, is a non-parametric statistical measure used to assess the agreement or concordance between multiple raters or judges when they rank a set of items. It is often used when you have ordinal data (ranks) and you want to see if there is consistency or consensus among the raters. It is widely applied in research areas such as psychology, medicine, and social sciences, where multiple judges are asked to rank or rate subjects or...
01:19Multiple Sclerosis l: Introduction
Multiple sclerosis is a chronic autoimmune disease of the central nervous system (CNS) that affects the brain, spinal cord, and optic nerves. It is an inflammatory demyelinating disorder and a leading cause of neurological disability in young adults.EpidemiologyMS commonly begins between 20 and 40 years of age and is twice as common in women. Its exact cause remains unclear, but genetic susceptibility contributes, with higher risk in first-degree relatives and identical twins. A greater...