Alopecia: association with resistance to thyroid hormones

Area of Science:

• Endocrinology
• Genetics
• Dermatology

Background:

• Resistance to thyroid hormone (RTH) syndrome is a genetic disorder resulting from mutations in the thyroid hormone beta receptor (TRbeta) gene.
• Common symptoms of RTH include goiter, learning disabilities, and growth delays.
• Alopecia areata (AA) is an autoimmune hair loss condition often associated with other autoimmune diseases.

Observation:

• This study describes a family with coexisting RTH and alopecia.
• The index patient, a boy, presented with RTH due to a novel heterozygous missense TRbeta mutation (I353V) and diffuse alopecia.
• The mutation was identified in his father and brother, who also have alopecia, and is suspected in other family members with goiter and alopecia.

Findings:

• A novel TRbeta mutation, I353V, was identified as the cause of RTH in the affected family members.
• The study found a correlation between this TRbeta mutation and various forms of alopecia within the family.
• Genetic analysis of the hairless (HR) gene did not reveal mutations in the family, ruling it out as the cause of alopecia in this context.

Implications:

• The findings suggest a potential causal link between the novel I353V TRbeta mutation and the observed alopecia phenotypes.
• This could be due to direct effects of thyroid hormone unresponsiveness in hair follicles or modulated actions involving the HR gene.
• Further research is warranted to elucidate the precise mechanisms connecting RTH and alopecia.