Related Experiment Video

Updated: Jun 13, 2026

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease
09:34

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease

Published on: April 4, 2018

SCN5A allelic expression imbalance in African-Americans heterozygous for the common variant p.Ser1103Tyr

Stacy A S Killen1, Jennifer Kunic, Lily Wang

  • 1Department of Medicine, Vanderbilt University, Nashville, TN, USA.

BMC Medical Genetics
|May 18, 2010
PubMed

Insights

Allelic expression imbalance of the SCN5A-p.Ser1103Tyr variant occurs in African-Americans. However, this genetic finding alone does not appear to increase the risk of sudden infant death syndrome (SIDS).

Area of Science:

  • Genetics
  • Cardiology
  • Molecular Biology

Background:

  • The SCN5A-p.Ser1103Tyr genetic variant is common among African-Americans and linked to sudden death risk.
  • Heterozygous carriers may exhibit unequal expression of wild-type and variant alleles.
  • Predominance of the variant allele could potentially elevate sudden death risk.

Purpose of the Study:

  • To investigate allele-specific expression of SCN5A-p.Ser1103Tyr in African-American infants.
  • To determine if allelic expression imbalance is associated with sudden infant death syndrome (SIDS).

Main Methods:

  • Quantified allele-specific expression of SCN5A-p.Ser1103Tyr using real-time RT-PCR.
  • Analyzed heart tissue from heterozygous African-American infants who died from SIDS or other causes.
  • Tested for allelic expression imbalance.

Main Results:

  • Significant allelic expression imbalance was observed in 50% of heterozygous infant hearts.
  • A significant bimodal distribution of log2 allelic expression ratios was found (p < 0.0001).
  • No significant differences in expression ratios were found between SIDS and non-SIDS groups.

Conclusions:

  • Allelic expression imbalance of SCN5A-p.Ser1103Tyr is present in heterozygous African-Americans.
  • This imbalance alone does not appear to be a risk marker for SIDS.
  • Further research may be needed to understand the full implications of this variant.
Abstract

More Related Videos

An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations10:17

An Allele-specific Gene Expression Assay to Test the Functional Basis of Genetic Associations

Published on: November 3, 2010

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation07:15

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation

Published on: January 16, 2019

Related Concept Videos

Comparing Copy Number Variations and SNPs02:26

Comparing 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%...
Epistasis Analysis01:09

Epistasis Analysis

Although Mendel chose seven unrelated traits in peas to study gene segregation, most traits involve multiple gene interactions that create a spectrum of phenotypes. When the interaction of various genes or alleles at different locations influences a phenotype, this is called epistasis. Epistasis often involves one gene masking or interfering with the expression of another (antagonistic epistasis). Epistasis often occurs when different genes are part of the same biochemical pathway. The...
Multiple Allele Traits01:49

Multiple Allele Traits

The Concept of Multiple Allelism
Multiple Allele Traits01:49

Multiple Allele Traits

The Concept of Multiple Allelism
Single Nucleotide Polymorphisms-SNPs01:05

Single Nucleotide Polymorphisms-SNPs

A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,...
Genetic Lingo01:11

Genetic Lingo

Overview