A novel MPLKIP-variant in three Finnish patients with non-photosensitive trichothiodystrophy type 4

Am J Med Genet A. 2021 Jun;185(6):1875-1882. doi: 10.1002/ajmg.a.62168. Epub 2021 Mar 17.


Trichothiodystrophy is a group of multisystem neuroectodermal disorders with dysplastic hair as the cardinal symptom. We describe three patients from two Finnish families in whom whole-exome sequencing revealed a novel homozygous variant, c.26del, p.(Pro9Glnfs*144) in the MPLKIP-gene, confirming the diagnosis of non-photosensitive trichothiodystrophy type 4 (TTD4). The variant was confirmed by Sanger sequencing and inherited from unaffected carrier parents. This report adds to the literature by expanding the genetic and phenotypic spectra of MPLKIP-related trichothiodystrophy. We describe dysmorphic features in the patients and provide a comparison of clinical characteristics in patients with TTD4 reported to date.

Keywords: C7orf11; TTD4; TTDN1; tiger tail; trichorrhexis; trichoschisis.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics*
  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Female
  • Finland / epidemiology
  • Genetic Predisposition to Disease*
  • Homozygote
  • Humans
  • Infant
  • Male
  • Mutation / genetics
  • Pedigree
  • Phenotype
  • Trichothiodystrophy Syndromes / epidemiology
  • Trichothiodystrophy Syndromes / genetics*
  • Trichothiodystrophy Syndromes / pathology
  • Young Adult


  • Adaptor Proteins, Signal Transducing
  • MPLKIP protein, human