Auto-immune disorders in a child with PIK3CD variant and 22q13 deletion

Eur J Med Genet. 2018 Oct;61(10):631-633. doi: 10.1016/j.ejmg.2018.04.008. Epub 2018 Apr 17.

Abstract

22q13 deletion syndrome is a genetic disorder caused by the deletion or disruption of the segment of the long arm of chromosome 22. The characteristic clinical features of this syndrome include delayed expressive speech, autistic behavior and hypotonia, and clinically severe complications associated with autoimmunity are rarely reported. We herein report a girl with 22q13 deletion syndrome complicated with multiple inflammatory and autoimmune diseases during early childhood. We performed whole-exome sequencing to identify the genes responsible for her autoimmune diseases and identified the de novo variant p.R512W in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta (PIK3CD) gene. We suspected it to be the disease-causing variant at the conserved residue in PIK(3)C p110δ. Alternatively, haplo-insufficiency of SHANK3 or other genes by 22q13 deletion and the PIK3CD variant might have synergistically contributed to the onset of the distinctive clinical manifestations in this patient.

Keywords: 22q13 deletion syndrome; Autoimmunity; PIK3CD gene; Whole-exome sequencing.

Publication types

  • Case Reports

MeSH terms

  • Autoimmune Diseases / diagnosis
  • Autoimmune Diseases / genetics*
  • Chromosome Deletion
  • Chromosome Disorders / diagnosis
  • Chromosome Disorders / genetics*
  • Chromosome Disorders / immunology
  • Chromosomes, Human, Pair 22 / genetics
  • Chromosomes, Human, Pair 22 / immunology
  • Class I Phosphatidylinositol 3-Kinases / genetics*
  • Female
  • Humans
  • Infant
  • Mutation

Substances

  • Class I Phosphatidylinositol 3-Kinases
  • PIK3CD protein, human

Supplementary concepts

  • Telomeric 22q13 Monosomy Syndrome