New genetic cause discovered for photosensitive blood disorder
The research team initially identified a family from Northern France in which the proband, or starting point for the genetic study of the family, suffered from EPP of unknown cause. The data collected from the proband indicated that she was affected by an unusual form of EPP. Among the proband's family members, only her father and uncle presented with indicators associated with mild photosensitivity but showed no clinical symptoms of EPP. CLPX is a gene that controls mitochondrial unfoldase, an enzyme that carries out a balancing step in actively unfolds selected proteins for "protein quality control" during heme biosynthesis by catalytically activating the rate-limiting step enzyme, ALAS, or degrading ALAS protein. Researchers found that a dominant mutation in CLPX inherited by members of this family reduced the degradation associated with one of its target proteins, ALAS, which subsequently led to the accumulation of protoporphyrin IX (PPIX). Abnormal accumulation o...