Mutations in the PIGW gene associated with hyperphosphatasia and mental retardation syndrome: a case report

BMC Pediatr. 2019 Feb 27;19(1):68. doi: 10.1186/s12887-019-1440-8.


Background: Mutations in the PIGV, PIGO, PIGL, PIGY, PGAP2, PGAP3, and PIGW genes have recently been reported to cause hyperphosphatasia accompanied by mental retardation syndrome (HPMRS); the latter is an autosomal-recessive neurological disorder typically characterised by recurrent seizures, intellectual disability, and distinct facial features. Here, we report an extremely rare case of a Chinese boy with compound heterozygous PIGW mutations who suffers from severe pneumonia, mental retardation, and epilepsy.

Case presentation: A 70-day-old boy presented with fever and cough over 20 days in duration at the time of admission. At the age of 6 months, unusual facial features were apparent, and seizures were clinically observed, accompanied by obvious cognitive delay. Next-generation sequencing identified novel PIGW c.178G > A and c.462A > T mutations, confirmed by Sanger sequencing.

Conclusions: Mutations in the PIGW gene in infants can cause various symptoms and multiple anomalies. Next-generation sequencing efficiently detects such mutations. The compound PIGW mutations that we describe expand the genotype/phenotype spectrum of HPMRS and may aid in clinical treatment.

Keywords: Alkaline phosphatase; Delayed cognitive development; Epilepsy; PIGW.

Publication types

  • Case Reports

MeSH terms

  • Abnormalities, Multiple / diagnosis
  • Abnormalities, Multiple / genetics*
  • Acyltransferases / genetics*
  • Epilepsy / diagnosis
  • Facies
  • Glycosylphosphatidylinositols / genetics*
  • High-Throughput Nucleotide Sequencing
  • Humans
  • Infant
  • Intellectual Disability / diagnosis
  • Intellectual Disability / genetics*
  • Male
  • Membrane Proteins / genetics*
  • Phosphorus Metabolism Disorders / diagnosis
  • Phosphorus Metabolism Disorders / genetics*
  • Pneumonia / diagnosis
  • Point Mutation*
  • Syndrome


  • Glycosylphosphatidylinositols
  • Membrane Proteins
  • Acyltransferases
  • PIGW protein, human

Supplementary concepts

  • Hyperphosphatasia with Mental Retardation