Identification of a Homozygous Missense Mutation in the TYR Gene in a Chinese Family with OCA1

Curr Med Sci. 2018 Oct;38(5):932-936. doi: 10.1007/s11596-018-1965-3. Epub 2018 Oct 20.

Abstract

Oculocutaneous albinism (OCA) is an autosomal recessive pigmentation abnormality, characterized by variable hair, skin, and ocular hypopigmentation. OCA1 is the most frequent subtype of OCA, caused by mutations in the tyrosinase gene (TYR). In this study, we investigated the genetic mutation of a Chinese family with a female OCA patient who came for genetic counseling before pregnancy. Complete physical examination was performed, and DNA from blood samples was collected from the family members. Mutations of TYR, OCA2, and SLC45A2 genes were examined in the proband, and verified in her parents by Sanger sequencing. Large deletion or duplication of TYR and OCA2 genes was detected by multiplex ligation-dependent probe amplification (MLPA). A homozygous TYR c.307T>C (p.Cys103Arg) missense mutation was identified in the proband, and both parents were heterozygous carriers. No large deletion or duplication was found in the proband. This mutation was absent in 1000G, ExAC, or HGMD database, and multiple lines of in silico tools supported a deleterious effect. These results suggest that TYR c.307T>C mutation might be responsible for OCA1, and our study further expands the mutation spectrum of OCA1 in the Chinese population.

Keywords: TYR; multiplex ligation-dependent probe amplification; mutation; oculocutaneous albinism.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Albinism, Oculocutaneous / genetics*
  • Albinism, Oculocutaneous / pathology
  • Computer Simulation
  • Female
  • Genetic Predisposition to Disease*
  • Genotype
  • Homozygote
  • Humans
  • Monophenol Monooxygenase / genetics*
  • Mutation, Missense
  • Pedigree

Substances

  • Monophenol Monooxygenase