People often ask, “How many individuals are affected by ectodermal dysplasias?” It’s a challenging question to answer, since they are rare conditions. In the past, studies to determine prevalence were prohibitively expensive. However, advances in technology and genetics have allowed a National Foundation for Ectodermal Dysplasias (NFED) research team to develop estimates for several of the most common types of ectodermal dysplasias. We are excited to share their findings with you!
By Drs. Clayton Butcher and Timothy Fete
Ectodermal dysplasias are a group of rare disorders. Despite improvements in genetic testing, making it easier to confidently diagnose an individual, there have not been many studies looking at how many individuals are affected by an ectodermal dysplasia.
A recent study published in JAMA Dermatology by Herlin et al was based on comprehensive dental and medical records in Denmark. The estimated birth prevalence for all ectodermal dysplasias combined was 14.5 per 100,000 births, and the birth prevalence for x-linked hypohidrotic ectodermal dysplasia (XLHED) was 2.8 per 100,000.
Why is it important to know how many individuals are affected with ectodermal dysplasias?
It is often important to know approximately how many individuals are affected by a disorder. For example, organizations like the NFED are commonly in discussions with various private groups, researchers, and government agencies working on ways to increase ectodermal dysplasia research, develop potential treatment options, and finding ways to assure affected individuals are better supported.
During these discussions, it is common to ask the prevalence rate (i.e. the number of people within the population who have a particular condition). The lack of reliable prevalence data was further identified in the NFED’s sponsored 2021 international conference, “Translating Discovery to Therapy”, as one of the five barriers to developing new therapies.
Improving What is Known About the Prevalence of Some of the More Common Ectodermal Dysplasia
Several of the NFED’s staff and Scientific Advisory Council members, along with help from the prevalence working group established following the 2021 International Research Conference, worked with the Department of Biomed Informatics at the University of Missouri School of Medicine to determine more reliable prevalence rates for some of the common ectodermal dysplasias. The results were recently published in the American Journal of Medical Genetics.
Our Methods
Since ectodermal dysplasias are so rare, a large database with data from over 100 healthcare systems, known as Oracle EHR Real-World Data, was utilized since it allowed for an easier way to examine a larger portion of the population. To identify potential individuals affected by a particular ectodermal dysplasia, a combination of diagnosis codes was used based upon common and unique features of each ectodermal dysplasia.
Over 64 million individuals were examined within the database and estimated prevalence rates for hypohidrotic ectodermal dysplasia (HED), ectodermal dysplasia and immunodeficiency (EDAID1), Clouston syndrome, ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome, ankyloblepharon-ectodermal defects-cleft lip and/or palate (AEC) syndrome, focal dermal hypoplasia (Goltz syndrome), and incontinentia pigmenti (IP) were determined.
Importance of This Study
As mentioned, knowing the prevalence rate of a condition helps when discussing with various groups, government agencies, and researchers making decisions on important aspects of the care, treatment, and support of affected individuals. The above study is the largest to ever look at the prevalence rates of many of the ectodermal dysplasias.
In addition, it for the first time provides an estimated prevalence for AEC as well as focal dermal hypoplasia.
Clayton J. Butcher, M.D. is a physician at the University of Missouri – Columbia and practices both internal medicine and pediatrics. Timothy J. Fete, M.D., M.P.H. is the Emeritus Professor and Chairman of the Department of Child Health (Pediatrics) at the University of Missouri School of Medicine. Both are members of the NFED Scientific Advisory Council and guest bloggers.