Researchers in Canada investigate methods using DNA methylation to identify fetal alcohol spectrum disorder in the absence of obvious physical signs.
Fetal alcohol spectrum disorder (FASD) is a common preventable cause of developmental disability in children. The many presentations of fetal alcohol spectrum disorder include physical abnormalities, stunted growth, cognitive and behavioral deficits, and motor, sensory, and immune system impairments. Fetal alcohol syndrome (FAS) lies on the most severe end of the spectrum and is characterized by slow growth, distinct types of facial malformations, and problems with the central nervous system.
Most children are diagnosed with fetal alcohol syndrome early in life because of obvious facial deformities. However, doctors have more trouble identifying children who fall on less severe parts of the spectrum because they lack the obvious physical characteristics of fetal alcohol syndrome. Nonetheless, the cognitive and behavioral deficits associated with fetal alcohol spectrum disorder can be serious even when other physical problems are absent.
Because early diagnosis of fetal alcohol spectrum disorder is a strong predictor of positive outcomes, better early-screening tools are needed to identify at-risk children. Typically, doctors rely on mothers to self-report prenatal alcohol use. But this is not always accurate and often leads to an underestimation of alcohol consumption during pregnancy.
Until recently, very few screening tools were available to help diagnose children at risk for fetal alcohol spectrum disorder. However, a Canadian study published in Clinical Epigenetics describes a method to identify and predict fetal alcohol spectrum disorder.
What Can Our DNA Tell Us About Early Exposure to Alcohol?
Researchers looked at changes in DNA to identify early exposure to alcohol. These types of changes fall into the category of epigenetics, which refers to modifications of DNA that may change how genes function without changing the DNA sequence. Specifically, DNA methylation (the addition of a methyl group to certain parts of a DNA sequence) is a useful biomarker for environmental exposure and disease.
In the current study, the DNA methylation patterns of 48 individuals (24 with fetal alcohol spectrum disorder and 24 without, ages 3.5-18 years) were analyzed using a test designed to measure 485,512 methylation sites across the human genome. Using information gathered from these arrays, the researchers were able to find a specific DNA methylation pattern associated with fetal alcohol spectrum disorder.
These findings represent a “stepping-stone” towards the ability to use epigenetic biomarkers for the diagnosis of fetal alcohol spectrum disorder and could potentially be developed to diagnose other developmental disorders. Since an early, reliable diagnosis increases the success of available treatments, these results are invaluable.
Written by Cindi A. Hoover, Ph.D.
Reference: Lussier AA, Morin AM, Maclsaac JL, Salmon J, Weinberg J, Reynolds JN, Pavlidis P, Chudley AE, Kobor MS. DNA methylation as a predictor of fetal alcohol spectrum disorder. Clinical Epigenetics; 2018, 10:5. DOI 10.1186/s13148-018-0439-6