Title:Different Phenotypes of Schimke Immuno-Osseous Dysplasia (SIOD) in
Two Sisters with the Same Mutation in the SMARCAL1 Gene
Volume: 22
Issue: 8
Author(s): Ana Castellano-Martinez, Silvia Acuñas-Soto, Raquel De la Varga-Martinez, Moises Rodriguez-Gonzalez*, Francisco Mora-Lopez, Marianela Iriarte-Gahete and Virginia Roldan-Cano
Affiliation:
- Department of Pediatric Cardiology,
Puerta del Mar University Hospital, Cadiz, Spain
Keywords:
Schimke immuno-osseus dysplasia, SMARCAL1, nephrotic syndrome, end-stage kidney disease, cardiovascular risk, children.
Abstract:
Background: Schimke immuno-osseous dysplasia (SIOD) is a very rare autosomal
recessive genetic disease caused by mutations in the SMARCAL1 gene. It is characterized by
spondyloepiphyseal dysplasia, T-cell immunodeficiency, hypercromic nevi, hypercholestero-lemia,
and steroid-resistant nephrotic syndrome with progressive renal failure to end-stage kidney
disease.
Case Presentation: We report two cases of SIOD in sisters, diagnosed after the debut of nephrotic
syndrome. Both had a personal history of short stature, acetabular hip dysplasia, and hypercholesterolemia.
The first case, a 6-year-old girl, presented peripheral refractory edema, severe arterial
hypertension, and progressive decrease of the glomerular filtration rate. Steroid-resistance of
nephrotic syndrome was confirmed, treated with tacrolimus without response. Renal function
worsened over the following 4 months, so haemodialysis was started. Her sister, a 5-year-old girl,
had the steroid-resistant nephrotic syndrome and normal blood pressure and renal function under
enalapril treatment. In view of the suspicion of SIOD, genetic studies were carried out, revealing
the same mutation in homozygosis.
Conclusion: SIOD has a variable expression with multi-systemic involvement with a short life
expectancy. Early diagnosis is important, which can encourage the early start of treatment and
anticipation of complications that may be life-threatening.
