Germline deletion and a somatic mutation of the PRKAR1A gene in a Carney complex-related pituitary adenoma

Eur J Endocrinol. 2015 Jan;172(1):K5-10. doi: 10.1530/EJE-14-0685. Epub 2014 Oct 21.

Abstract

Objective: The objective was to assess involvement of loss of the PRKAR1A gene encoding a type 1α regulatory subunit of cAMP-dependent protein kinase A located on 17q24 in a Carney complex (CNC)-related pituitary adenoma.

Design: We investigated aberrations of the PRKAR1A gene in a CNC patient with a GH-producing pituitary adenoma, whose family has three other members with probable CNC.

Methods: A gene mutation was identified by a standard DNA sequencing method based on PCR. DNA copy number was measured to evaluate allelic loss on 17q24 by quantitative PCR. The breakpoints of deletion were determined by cloning a rearranged region in the deleted allele.

Results: A PRKAR1A mutation of c.751_758del8 (p.S251LfsX16) was found in genomic DNA obtained from a pituitary adenoma, but not leukocytes from the patient. Reduced DNA copy number at loci including the PRKAR1A gene on 17q24 was detected in both the tumor and leukocytes, suggesting a deletion at the loci at the germline level. The deletion size was determined to be ∼ 0.5 Mb and this large deletion was also found in two other family members.

Conclusion: This is the first case showing a CNC-related pituitary adenoma with the combination of somatic mutation and a large inherited deletion of the PRKAR1A gene. Biallelic inactivation of PRKAR1A appears to be necessary for the development of CNC-related pituitary adenoma.

Publication types

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

MeSH terms

  • Adenoma / diagnosis
  • Adenoma / genetics*
  • Aged
  • Carney Complex / diagnosis
  • Carney Complex / genetics*
  • Cyclic AMP-Dependent Protein Kinase RIalpha Subunit / genetics*
  • Female
  • Gene Deletion*
  • Germ-Line Mutation / genetics*
  • Humans
  • Middle Aged
  • Pedigree
  • Pituitary Neoplasms / diagnosis
  • Pituitary Neoplasms / genetics*
  • Young Adult

Substances

  • Cyclic AMP-Dependent Protein Kinase RIalpha Subunit
  • PRKAR1A protein, human