Dr. Walt Holleran


Dr. Walk Holleran is a research professor and an expert in the metabolism of specific lipids present in the skin and other tissues, called “sphingolipids” or “ceramides.” He has been studying the function of the skin as a barrier, and the role of ceramides in forming the barrier in the outermost layers of the skin, called the stratum corneum. Concentrated and organized layers of lipids, including ceramides, are found between cells in the stratum corneum. This combination of “dead” skin cells and surrounding lipids constitutes the primary barrier between humans and their environment.

As you are aware, recent work by Drs. Bejaoui and Brown revealed that specific gene alterations in affected family members include changes in the gene for an enzyme in ceramide production, called serine palmitoyltransferase (or “SPT” for short). Dr. Holleran, who has conducted numerous studies into the role of SPT in normal skin function, was contacted by Dr. Bejaoui to help determine whether the skin might also be altered in affected individuals.

To this end, Dr. Holleran and a colleague, Dr. Joachim Fluhr, visited last summer with a number of family members to measure specific parameters of skin structure and function. Their initial results show that skin of affected family members may have a very slight delay in the ability to recover from a mild challenge; that is, the outermost layers of dead skin cells and surrounding lipids were removed using sequential applications of tape. However, initial microscopy studies have so far revealed very little difference in the structure of the stratum corneum in affected vs. nonaffected individuals.

Although these preliminary results suggest that the outermost layers of skin may be altered in affected individuals, it must be stressed that the relationship of these findings to the progression of symptoms will require further study and analysis. Dr. Holleran hopes to continue these studies in conjunction with Drs. Bejaoui and Brown, and to determine whether skin structure and function relate to progression of symptoms in affected family members.