Somatic mosaic monosomy 7 and UPD7q in a child with MIRAGE syndrome caused by a novel SAMD9 mutation

Pediatr Blood Cancer. 2019 Apr;66(4):e27589. doi: 10.1002/pbc.27589. Epub 2018 Dec 19.

Abstract

MIRAGE syndrome caused by mutations in SAMD9 is associated with potential loss of chromosome 7 (-7/7q-) and an increased risk to develop myelodysplastic syndrome (MDS). We report a case of MIRAGE syndrome, caused by a novel SAMD9 mutation p.Leu641Pro, leading to characteristic clinical features as well as to the coexistence of cells with monosomy 7 (20%) and with uniparental disomy of long arm of chromosome 7 (UPD7q). In contrast to previously reported MIRAGE patients with -7/7q- developing MDS, our patient achieved complete cytogenetic remission of monosomy 7. As UPD7q remained unchanged, it seems to be a protective factor against MDS.

Keywords: MIRAGE syndrome; SAMD9 mutation in mosaic form; UPD7q; monosomy 7; myelodysplastic syndrome.

Publication types

  • Case Reports

MeSH terms

  • Child, Preschool
  • Chromosome Deletion*
  • Chromosomes, Human, Pair 7
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Male
  • Mutation*
  • Myelodysplastic Syndromes / genetics*
  • Myelodysplastic Syndromes / pathology
  • Myelodysplastic Syndromes / therapy*
  • Proteins / genetics*

Substances

  • Intracellular Signaling Peptides and Proteins
  • Proteins
  • SAMD9 protein, human

Supplementary concepts

  • Chromosome 7, monosomy