A Frame-Shift Mutation in CAV1 Is Associated with a Severe Neonatal Progeroid and Lipodystrophy Syndrome

PLoS One. 2015 Jul 15;10(7):e0131797. doi: 10.1371/journal.pone.0131797. eCollection 2015.

Abstract

A 3-year-old female patient presenting with an unknown syndrome of a neonatal progeroid appearance, lipodystrophy, pulmonary hypertension, cutis marmorata, feeding disorder and failure to thrive was investigated by whole-genome sequencing. This revealed a de novo, heterozygous, frame-shift mutation in the Caveolin1 gene (CAV1) (p.Phe160X). Mutations in CAV1, encoding the main component of the caveolae in plasma membranes, cause Berardinelli-Seip congenital lipodystrophy type 3 (BSCL). Although BSCL is recessive, heterozygous carriers either show a reduced phenotype of partial lipodystrophy, pulmonary hypertension, or no phenotype. To investigate the pathogenic mechanisms underlying this syndrome in more depth, we performed next generation RNA sequencing of peripheral blood, which showed several dysregulated pathways in the patient that might be related to the phenotypic progeroid features (apoptosis, DNA repair/replication, mitochondrial). Secondly, we found a significant down-regulation of known Cav1 interaction partners, verifying the dysfunction of CAV1. Other known progeroid genes and lipodystrophy genes were also dysregulated. Next, western blotting of lysates of cultured fibroblasts showed that the patient shows a significantly decreased expression of wild-type CAV1 protein, demonstrating a loss-of-function mutation, though her phenotype is more severe that other heterozygotes with similar mutations. This phenotypic variety could be explained by differences in genetic background. Indications for this are supported by additional rare variants we found in AGPAT2 and LPIN1 lipodystrophy genes. CAV1, AGPAT2 and LPIN1 all play an important role in triacylglycerol (TAG) biosynthesis in adipose tissue, and the defective function in different parts of this pathway, though not all to the same extend, could contribute to a more severe lipoatrophic phenotype in this patient. In conclusion, we report, for the first time, an association of CAV1 dysfunction with a syndrome of severe premature aging and lipodystrophy. This may contribute to a better understanding of the aging process and pathogenic mechanisms that contribute to premature aging.

Publication types

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

MeSH terms

  • Acyltransferases / genetics
  • Caveolin 1 / genetics*
  • Child, Preschool
  • Codon, Nonsense
  • Female
  • Fetal Growth Retardation / genetics*
  • Fetal Growth Retardation / pathology
  • Frameshift Mutation
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Lipodystrophy, Congenital Generalized / genetics*
  • Lipodystrophy, Congenital Generalized / pathology
  • Phenotype
  • Phosphatidate Phosphatase / genetics
  • Progeria / genetics*
  • Progeria / pathology
  • Sequence Analysis, RNA
  • Severity of Illness Index

Substances

  • Caveolin 1
  • Codon, Nonsense
  • Acyltransferases
  • 2-acylglycerophosphate acyltransferase
  • LPIN1 protein, human
  • Phosphatidate Phosphatase

Supplementary concepts

  • Lipodystrophy, Congenital Generalized, Type 3
  • Progeroid syndrome, neonatal

Grants and funding

Funding was received from the State of Arizona DHS and several anonymous donors. IS is a postdoctoral researcher of the FWO-Vlaanderen. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The Center for Rare Childhood Disorders receives funding from multiple donors and fundraising efforts organized through the TGen Foundation. Robyn Nebrich (Assistant Development Director) and Terry McManus (Vice President of Strategic Initiatives) would be happy to speak with you about the funding for the Center. They can be reached at: Robyn Nebrich (Email: rnebrich@tgen.org 602.343.8638 | c: 480.235.5811 | f: 602.343.8441) and Terry McManus (Email: tmcmanus@tgen.org 602.343.8527 | c: 480.316.4537 | f: 602.343.8441).