Ectodermal Dysplasia – Type Unknown
In 2019, the National Foundation for Ectodermal Dysplasias (NFED) partnered with Baylor-Hopkins Center for Mendelian Genomics in the Department of Molecular and Human Genetics at Baylor College of Medicine on a a research study to identify a specific ectodermal dysplasia diagnosis for all individuals on our database.
Richard Alan Lewis, M.D., M.S. was one of the primary investigators and a former member of theNFED Scientific Advisory Council. This study is now closed and no longer accepting new participants..
Many individuals have a diagnosis of ectodermal dysplasia but do not know which of the 50+ types they have. We call this “type unknown.” There are numerous benefits of having a specific diagnosis.
In this joint program, families which never had a genetic explanation for the features of their ectodermal dysplasia were enrolled in a research program that undertook intensive studies of their genetics, both to find currently unknown genes responsible for the ectodermal dysplasia and to open new understandings of what is the normal function of that gene.
Researchers were able to identify the gene that causes ectodermal dysplasia for 10 families. Several additional families had molecular findings that are undergoing studies to confirm the diagnosis. A number of families still do not have a definitive molecular diagnosis.
According to Jennifer Posey, M.D., Ph.D., who was the co-principal investigator of the Rare Disease Program with Dr. Lewis:
“In some cases, the underlying genetic variation may not be readily detectable using standard short-read sequencing approaches. To address this possibility, we have initiated a pilot study using long-read sequencing, an emerging technology that enables improved detection of complex structural variation, repeat expansions, and other genomic features that can be challenging to resolve with conventional sequencing methods.”
With support from National Institutes of Health (NIH) funding, the long read sequencing pilot study is currently underway. If long-read sequencing demonstrates added diagnostic yield, it may represent an important next step for unresolved families within this cohort and inform future diagnostic workflows.