Desmosterolosis presenting with multiple congenital anomalies

Eur J Med Genet. 2018 Mar;61(3):152-156. doi: 10.1016/j.ejmg.2017.11.009. Epub 2017 Nov 23.

Abstract

Desmosterolosis is a rare multiple congenital anomaly syndrome caused by a defect in the enzyme 3-beta-hydroxysterol delta-24-reductase (DHCR24) in the cholesterol biosynthesis pathway. Defects in this enzyme cause increased level of the cholesterol precursor desmosterol while disrupting development of cholesterol, impacting embryogenesis. A total of 9 cases of desmosterolosis have been reported to date. We report a 20-month-old male from consanguineous parents with multiple congenital anomalies including corpus callosum hypoplasia, facial dysmorphism, cleft palate, pectus deformity, short and wide neck and distal contractures. On analysis of the regions of homozygosity found by microarray, we identified DHCR24 as a candidate gene. Sterol quantitation showed a desmosterol level of 162 μg/mL (nl: 0.82 ± 0.48). Genetic testing confirmed the diagnosis with a homozygous likely pathogenic mutation (p.Glu191Lys) in the DHCR24 gene. Our case expands the known diagnostic spectrum for Desmosterolosis. We suggest considering Desmosterolosis in the differential diagnosis of patients who present with concurrent agenesis of the corpus callosum with white matter atrophy and ventriculomegaly, retromicrognathia with or without cleft palate, hand contractures, and delay of growth and development. Children of consanguineous mattings may be at higher risk for rare recessive disorders and testing for cholesterol synthesis defect should be a consideration for affected children. Initial evaluation can be performed using sterol quantitation, followed by genetic testing.

Keywords: Cholesterol biosynthesis defect; Congenital anomalies; Consanguinity; Desmosterol; Inborn errors of metabolism.

Publication types

  • Case Reports

MeSH terms

  • Abnormalities, Multiple / diagnosis*
  • Abnormalities, Multiple / genetics
  • Adult
  • Developmental Disabilities / diagnosis*
  • Developmental Disabilities / genetics
  • Female
  • Homozygote
  • Humans
  • Infant
  • Lipid Metabolism, Inborn Errors / diagnosis*
  • Lipid Metabolism, Inborn Errors / genetics
  • Male
  • Mutation*
  • Nerve Tissue Proteins / genetics*
  • Oxidoreductases Acting on CH-CH Group Donors / genetics*
  • Pedigree
  • Prognosis

Substances

  • Nerve Tissue Proteins
  • Oxidoreductases Acting on CH-CH Group Donors
  • DHCR24 protein, human

Supplementary concepts

  • Desmosterolosis