New mutation in the PTEN gene in a Brazilian patient with Cowden's syndrome

Arq Bras Endocrinol Metabol. 2012 Nov;56(8):592-6. doi: 10.1590/s0004-27302012000800022.

Abstract

Cowden syndrome is characterized by hamartomatous polyps, trichilemmomas, increased risk of developing neoplasms, and is associated with germline mutations in the PTEN gene. We searched for germline mutations in PTEN in a 49-year-old female patient who presented trichilemmoma with previous history of breast carcinoma, and thyroidectomy for a thyroid nodule. We also searched for somatic mutations in breast and thyroid tumoral tissues. DNA was extracted from peripheral leukocytes, paraffin samples of breast carcinoma, and cytological smears of thyroid nodule fine-needle aspiration biopsy, whose final histopathological diagnosis was adenomatous goiter. PTEN was amplified and sequenced. We identified a novel mutation, due to a T>A inversion at position 159 and A>T inversion at position 160, leading to valine-to-aspartic acid substitution at position 53. The p.Val53Asp was also found in homozygous state in samples obtained from adenocarcinoma breast and thyroid biopsy, denoting loss of heterozygosity. Here, we demonstrated a novel germline mutation in PTEN, as well as somatic loss of the wild-type PTEN allele in breast and thyroid tumors in a patient with Cowden syndrome.

Publication types

  • Case Reports

MeSH terms

  • Breast Neoplasms / genetics*
  • Female
  • Genetic Markers
  • Hamartoma Syndrome, Multiple / genetics*
  • Humans
  • Middle Aged
  • Mutation / genetics*
  • PTEN Phosphohydrolase / genetics*
  • Thyroid Neoplasms / genetics*

Substances

  • Genetic Markers
  • PTEN Phosphohydrolase