Rare Hair Loss Condition Linked to PLEC Gene Mutation and EBS Subtype for Only 2nd Time
A rare case of hair loss associated with PLEC gene mutation and epidermolysis bullosa simplex with muscular dystrophy was reported for the second time in a patient from the Azores. The case report was published in the journal BMC Dermatology.
Epidermolysis bullosa (EB) is caused by genetic mutations that affect skin structural proteins, leading to variable degrees of skin fragility. Four major types of the disease have been identified, each of which has several subtypes.
One of those subtypes is epidermolysis bullosa simplex with muscular dystrophy (EBS-MD). It is an autosomal recessive form of the disease, meaning it requires two copies of the mutated gene to cause symptoms to appear.
The primary clinical manifestation of EBS-MD is skin blistering with onset soon after birth or in early infancy. The secondary main characteristic of the disease is progressive muscle weakness, which may appear during infancy or later in life. Patients may also experience other symptoms such as nail disorders, abnormal dentition, and respiratory complications.
This EBS subtype has been linked to mutations in the PLEC gene, which encodes a protein that can be found in several tissues in the body, including the skin and muscles.
In the study, “A novel PLEC nonsense homozygous mutation (c.7159G > T; p.Glu2387*) causes epidermolysis bullosa simplex with muscular dystrophy and diffuse alopecia: a case report,” a Portuguese research team reported the case of a patient with EBS-MD who experienced hair loss (alopecia) due to the disease.
The patient, a 28-year-old woman from the Azorean island of São Miguel in Portugal, started to show hemorrhagic blisters in the skin and oral mucosa two days after she was born. By the age of 5 or 6 she experienced recurrent upper respiratory tract infections, and exhibited extensive nail dystrophy and hair weakness.
Despite these clinical features, the child developed normally with the exception of her weight, which was below normal standards.
With age, the skin blistering symptoms improved, but hair loss from the scalp and eyebrows progressively increased.
The first signs of muscle weakness were reported during adolescence and gradually progressed, impairing her physical activity until the patient was unable to perform daily activities.
A physical exam when she was an adult confirmed sparse, hemorrhagic blisters and crusts distributed throughout her body, diffuse non-scarring alopecia on the scalp and eyebrows, a nail disorder affecting all 20 nails, and dental problems. The patient also had difficulty speaking due to altered oral mucosa, and presented severe muscle atrophy in her extremities.
A neurological exam showed profoundly diminished reflexes. A blood workup did not indicate a hormonal alteration.
Genetic analysis revealed a new mutation in the PLEC gene, which researchers identified as Glu2387*. A computer simulation analysis indicated that the mutation would trigger the production of a shorter form of the encoded protein (called plectin) or could result in reduced levels of the protein.
Additional analyses are warranted to better understand the impact of this mutation and its relation to EBS-MD.
Diffuse alopecia is a very rare clinical feature associated with EBS-MD, and according to a literature review conducted by the researchers, this is only the second case study reporting such a scenario. Of note, the researchers emphasized that both cases had different mutations involving the PLEC gene.
The research team said it remains to be seen whether these uncommon cases of diffuse alopecia in EBS-MD are a result of PLEC gene mutations or from environmental factors.