Generalized Arterial Calcification in a Recipient Twin: Discordant Fetal Hemodynamics Result in Differing Phenotypes in Monozygotic Twins with an ABCC6 Mutation

Fetal Diagn Ther. 2017;41(3):234-236. doi: 10.1159/000444852. Epub 2016 Mar 17.


Recipients of the twin-twin transfusion syndrome (TTTS) often develop cardiac manifestations, but arterial calcification has rarely been reported. Generalized arterial calcification of infancy (GACI) is a genetic disorder with high infantile mortality. We report the case of a TTTS recipient with moderate cardiomyopathy at diagnosis who developed progressive calcification of the pulmonary arteries and aorta after successful in utero laser therapy. Postnatally, both twins were diagnosed with a heterozygous ABCC6 gene mutation associated with GACI. The recipient had progressive supravalvular pulmonary and aortic stenosis, was treated with bisphosphonate therapy, and successfully underwent cardiac surgery at 4 months of age. The donor twin with the same mutation remained phenotypically normal at 15 months of age. This case illustrates monozygotic fetuses with discordant in utero hemodynamics, with subsequent development of phenotypic differences. TTTS recipients with arterial calcifications should undergo genetic testing for GACI.

Keywords: Arterial calcification; Cardiomyopathy; Congenital heart disease; Genetic disorder; Monochorionic twins; Twin-twin transfusion syndrome.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Female
  • Fetofetal Transfusion / complications
  • Fetofetal Transfusion / diagnostic imaging
  • Fetofetal Transfusion / genetics*
  • Hemodynamics / physiology
  • Humans
  • Multidrug Resistance-Associated Proteins / genetics*
  • Mutation / genetics
  • Phenotype*
  • Pregnancy
  • Stenosis, Pulmonary Artery / complications
  • Stenosis, Pulmonary Artery / diagnostic imaging
  • Stenosis, Pulmonary Artery / genetics*
  • Twins, Monozygotic / genetics*
  • Vascular Calcification / complications
  • Vascular Calcification / diagnostic imaging
  • Vascular Calcification / genetics*


  • ABCC6 protein, human
  • Multidrug Resistance-Associated Proteins