A novel POC1A variant in an alternatively spliced exon causes classic SOFT syndrome: clinical presentation of seven patients

J Hum Genet. 2020 Jan;65(2):193-197. doi: 10.1038/s10038-019-0693-2. Epub 2019 Nov 26.

Abstract

Biallelic pathogenic variants in POC1A are ultra rare. They have been reported in 13 families as causing either Short stature, Onychodysplasia, Facial dysmorphism, and hypoTrichosis (SOFT) syndrome, or a milder partially overlapping phenotype, variant POC1A-related syndrome. This pleiotropic effect is likely precipitated by the variant's location and respective affected protein domain. Here, we describe seven patients from two consanguineous Omani families with classic SOFT syndrome and a novel homozygous POC1A variant (c.64G>T; p.(Val22Phe)), which is the first one described for the alternative exon 2. This result refines the POC1A mutational spectrum relevant for exertion of the described pleiotropic effect. Furthermore, six of our patients experienced recurrent mild to severe respiratory difficulties that have not been previously reported for SOFT syndrome and may be an underdiagnosed or a genotype-specific complication that warrants attention in future studies. Thus, our study unravels new aspects of the genotype-phenotype correlation suggested by previous reports.

MeSH terms

  • Abnormalities, Multiple / genetics*
  • Alternative Splicing
  • Cell Cycle Proteins / genetics*
  • Child
  • Child, Preschool
  • Consanguinity
  • Craniofacial Abnormalities / genetics*
  • Cytoskeletal Proteins / genetics*
  • Dwarfism / genetics*
  • Exons / genetics
  • Female
  • Genetic Association Studies*
  • Genotype
  • Humans
  • Hypotrichosis / genetics*
  • Male
  • Muscular Atrophy / genetics*
  • Mutation
  • Phenotype

Substances

  • Cell Cycle Proteins
  • Cytoskeletal Proteins
  • POC1A protein, human

Supplementary concepts

  • Facial Dysmorphism with Multiple Malformations