Mutations in the PIGW Gene Associated with Hyperphosphatasia and Mental Retardation Syndrome: a Case Report

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.