Trichothiodystrophy type 3 with a mutation in the GTF2H5 gene: A case report in Argentina.

Trichothiodystrophy is a rare neuroectodermal defect characterized by sparse and brittle hair, photosensitivity, intellectual disability, and short stature. With an incidence of 1.2 per million in Western countries, half of the reported cases have clinical and cellular photosensitivity associated with mutations in three subunits of the general transcription factor IIH complex, which is involved in transcription and nucleotide excision repair. Six patients with GTF2H5 mutations have been reported; this is the first report in Argentina. The patient was diagnosed at 3 years of age by "tiger tail banding" on polarized light microscopy, and at 9 years of age, it was confirmed by molecular biology. She presented growth retardation with more severe stunting and underweight than reported. Given the low prevalence and high clinical heterogeneity, a high index of suspicion is required for early diagnosis, interdisciplinary management, and genetic counseling.